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Case Study Questions for Class 8 Science Chapter 12 Friction

Last modified on: 10 months ago
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Here we are providing case study questions for CBSE Class 8 Science Chapter 12 Friction .

Case Study Questions

Question 1:

Friction is a force between two surfaces that are sliding, or trying to slide, across each other. Friction always works in the direction opposite to the direction in which the object is moving, or trying to move. It always slows a moving object down.

Friction also produces heat. If you rub your hands together quickly, you will feel them get warmer. Friction can be a useful force because it prevents our shoes slipping on the pavement when we walk and stops car tyres skidding on the road. When you walk, friction is caused between the tread on shoes and the ground. This friction acts to grip the ground and prevent sliding. Sometimes we want to reduce friction. For example, we use oil to reduce the friction between the moving parts inside a car engine. In many machines, friction is reduced by using ball bearings. The reduced friction means there is less wear on the moving parts and less heat produced.

i) When does friction arise? ii) Why should we apply oil on the hinges of the door? iii) Gymnasts apply some coarse substance on their hands. Why? iv) Explain why sportsmen use shoes with spikes.

i) Friction arises when the irregularities of the two surfaces interlock.

ii) Oils are one of the best lubricants and applying them on the door hinges reduces friction and eases functioning.

iii) Gymnasts apply the coarse substance on their hands to increase friction for a better grip.

iv) It is done to provide the shoes better grip on the ground.

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Friction Class 8 Case Study Questions Science Chapter 9

Last Updated on May 16, 2024 by XAM CONTENT

Hello students, we are providing case study questions for class 8 science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class 8 science. In this article, you will find case study questions for cbse class 8 science chapter 9 Friction.

Table of Contents

Case Study Questions on Friction

Question 1:

Read the given passage below and answer the question:

(I) The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. On the other hand, the force required to keep the object moving with the same speed is a measure of sliding friction. The sliding friction is slightly smaller than the static friction. When one body rolls over the surface of another body, the resistance to its motion is called rolling friction. Rolling reduces friction. It is always easier to roll than to slide a body over another.

Q.1. The following options show arrangement of types of friction according to decreasing order of applied friction. Select the correct order. (a) Rolling > Sliding > Static (b) Static > Rolling > Sliding (c) Sliding > Static > Rolling (d) Static > Sliding > Rolling

Difficulty Level: Easy

Ans. Option (d) is correct. Explanation: Rolling friction is least among all three types because the surface of wheels has minimal contact with the surface on which it rolls, thus minimising friction.

Q.2. In which of the following case one will have to apply maximum force? (a) Riding a bicycle (b) Trying to move a heavy rock from its resting place (c) Swimming in a pool (d) Drilling a hole in a wall

Ans. Option (b) is correct. Explanation: Stationary rock will experience static friction. Static friction is the highest; thus it will require maximum force or efforts to move it from its rest position.

Q.3. Oiling or greasing in machine parts: (a) Increases the friction between the parts (b) Decreases the friction between the parts (c) Both (a) and (b) are correct. (d) None of the above

Ans. Option (b) is correct.

Explanation: Oiling and greasing act as a lubricant. When oil, grease or graphite is applied between the moving part of a machine, a thin layer is formed there and moving surfaces do not directly rub against each other. Interlocking of irregularities is avoided to a great extent. Movement becomes smooth.

Q.4. Why static friction is more than sliding friction?

Ans. The friction is caused by the interlocking of irregularities in the two surfaces. It is obvious that the force of friction will increase if the two surfaces are pressed harder. The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. On the other hand, the force required to keep the object moving with the same speed is a measure of sliding friction. When the box starts sliding, the contact points on its surface, do not get enough time to lock into the contact points on the floor. So, the sliding friction is slightly smaller than the static friction.

Q.5. Classify the given examples into static, sliding and rolling friction Papers on a table, a box sliding on an inclined plain, car parked on a hill, ball moving on the ground, child playing on slide in a park, tyres of a bus.

Ans. Static Friction: Papers on a table, car parked on a hill. Sliding Friction: A box sliding on an inclined plain, child playing on slide in a park Rolling Friction: Ball moving on the ground, tyres of a bus.

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Crop production and management class 8 case study questions science chapter 1, topics from which case study questions may be asked.

Learn the concept of friction.
Understand the factors that affect frictional force.
Learn the different types of friction.
Understand the advantages and disadvantages of friction.
Learn the methods to increase or decrease friction.
Understand the concept of fluid friction and methods to reduce it.

The force which opposes the relative motion between two surfaces in contact is called friction. Friction is a necessary evil that makes us walk, write, hold things, etc. The liquids and gases also exert opposition forces on objects moving through them. This is called fluid friction.

Frequently Asked Questions (FAQs) on Friction Case Study Questions

Q1: what are case study questions for cbse examinations.

A1: Case study questions in CBSE examinations typically involve scenarios or real-life examples, requiring students to apply their understanding of concepts to solve problems or analyze situations.

Q2: Why are case study questions important for understanding class 8 science chapters?

A2: Case study questions provide a practical context for students to apply theoretical knowledge to real-world situations, fostering deeper understanding and critical thinking skills.

Q3: How should students approach answering case study questions for CBSE?

A3: Students should carefully read the case study, identify the key issues or problems presented, analyze the information provided, apply relevant concepts and principles of friction, and formulate well-supported solutions or responses.

Q4: Are there any resources available online for students to practice case study questions on class 8 science chapters for CBSE exams?

A4: Yes, several educational websites offer case study questions for CBSE students preparing for science examinations. We also offer a collection of case study questions for all classes and subject on our website. Visit our website to access these questions and enhance your learning experience.

Q5: How can students effectively prepare for case study questions on friction for CBSE exams?

A5: Effective preparation strategies include regular revision of concepts, solving practice questions, analyzing case studies from previous exams, seeking clarification on doubts, and consulting with teachers or peers for guidance and support.

Q6: How can teachers incorporate case study questions on friction class 8 science into classroom teaching?

A6: Teachers can integrate case studies into lesson plans, group discussions, or interactive activities to engage students in active learning, promote problem-solving skills, and facilitate a deeper understanding of concepts of friction.

Q7: Why soles of the rubber slippers become slippery after prolonged use?

A7: While walking the slipper’s sole and ground surface experiences friction which causes the sole to wear off.

Q8: What are lubricants? How do they work? Give two examples.

A8: The substances which reduce friction are called lubricants. Example Oil, grease, graphite etc. They work by forming a thin layer between machine parts. As a result, the moving surfaces do not directly rub against each other. Interlocking of irregularities is avoided to a great extent. Movement becomes smooth.

Q9: Will the force of friction come into play, when a rain drop rolls down a glass window pane?

A9: Yes, friction comes into play when two surfaces are in contact, e.g., glass and water in this case.

Q10: While playing tug of war, Preeti felt that the rope was slipping through her hands. Suggest a way out for her to prevent this.

A10: To prevent slipping the rope from her hands, Preeti has to make her hands somewhat non-smooth, so she can rub her hands by introducing the sand between them.

Friction Class 8 Case Study Questions Science Chapter 9

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Friction CBSE Class 8 Science Notes Chapter 12

What is friction.

Friction is a force that comes into play when two surfaces come in contact with each other.

The Frictional force or the force of Friction acts in the opposite direction of the motion of the object.

The force of Friction opposes the relative motion between the surfaces of two moving objects.

Figure 1 Force of Friction

Factors that can affect Friction

Figure 2 Contact between two surfaces

The irregularities of a surface: If we move an object with has an irregular or rough surface on another surface which is also irregular, the force of Friction will be high in this case and the movement of the object would be restricted.

The regularity of a surface or its smoothness : If the surfaces of either the objects or are smooth, the force of Friction would be less and the object would move easily over the surface. Even smooth surfaces have a certain irregularity.

If two surfaces are pressed hard: the force of Friction increases between two surfaces if they are pressed hard and hence the movement of the object becomes restricted. However, if there is no pressure the object can easily move.

Figure 3 Factors Affecting Friction

Types of Friction

Static Friction: The Frictional force that comes into play until an object starts moving is called static Friction. An object has to overcome the static Friction force in order to start its movement.

Sliding Friction: Sliding Friction comes into play whenever an object moves along the surface of another object. Such a movement is called ‘slide’. Hence, sliding Friction is the force that opposes the movement or slide of an object.

Rolling Friction: When an object is rolling on a surface the force of Friction which acts upon it is called rolling Friction.

Fluid Friction: When an object moves in a fluid, the fluid exerts a fluid Friction upon the object. It is also called air Friction (when the medium of travel is air) and viscous Friction (when the medium of travel is water).

Figure 4 Types of Friction

Advantages of Frictional Force

Frictional force is necessary for various purposes in our daily lives such as:

It allows us to walk on the earth surface.

It allows us to write with a pen on a surface or a paper.

It allows us to fix a nail in the wall.

A moving object would never be able to come to the state of rest without the Frictional force.

It would not be possible to drive any automobiles on the road without the Friction force.

It would not be possible to construct any buildings without the Frictional force.

Figure 5 Advantages of Frictional force

Disadvantages of Frictional Force

Frictional force results in wear and tear of objects such as the moving parts of a machine, the tyres of a vehicle, sole of the shoes etc.

It also results in the production of heat. In the case of machines, the production of heat leads to wastage of energy.

The Frictional force also leads to a decrease in the speed of a moving object or some time stops it.

It can lead to noise pollution in certain cases. For instance, aircrafts produce loud sound due to the resistance of the air.

Figure 6 Disadvantages of Frictional force

How can we reduce or increase Friction?

Increasing Friction: Sometimes we need to increase Friction so as to avoid slipping of objects, for example:

The sole of the shoes is grooved so that the Friction between our feet and ground increases and we can walk safely

The tyres are treaded so that they can have a better grip over the ground and allow the smooth movement of the vehicles.

Brake pads are used in bikes to stop them suddenly from moving by increasing the amount of Friction.

Kabaddi players rub their hands with soil which helps in increasing the Friction between the hands and allows them to have an easy grip of the opponent.

Gymnasts also apply a coarse substance so that they can have a better grip due to increased Friction in their hands.

Figure 7 Increasing Friction

Reducing Friction: Sometimes in order to have a smooth movement of an object we need to reduce Friction. For example,

The powder is sprinkled over the carrom board to decrease the Friction between the board’s surface and the striker. In this way, the surface of the carrom board becomes smooth.

Grease is used in bicycles and other motors or different parts of a machine to reduce Friction and increase their efficiency.

Oil is applied on the hinges of the door so that they can move easily.

Figure 8 Decreasing Friction

Applying substances like oil, grease or powder allows in smooth movement as they block the irregularities of a surface. The substances that can reduce the amount of Friction between different objects are called lubricants. However, we can never reduce Friction to a level of zero. There are always some irregularities present on the surface.

Figure 9 Lubricants

How wheels reduce Friction?

We know that when an object rolls over a surface rolling Friction is produced which resists its motion on the surface. However, its magnitude is lesser than the static and sliding Friction.

Wheels are circulating objects that turn around a center point.

The wheels allow an object to roll over a surface rather than allowing them to slide over the surface.

This results in less Friction and hence easy movement of the object.

Rolling Friction is also used in the parts of machines that are moving continuously.

In this way, the sliding Friction is removed with the help of rolling Friction and therefore the adverse effects of Friction such as the production of heat or wear and tear of the mechanical parts are also reduced.

For instance, ball bearings are being used in fans and bicycles to reduce Friction.

Figure 10 Ball Bearings

Fluid Friction

Figure 11 Fluid Friction

Air, water and other liquids collectively are called fluids. They also exert a Frictional force on the object that travels through them. Such a Friction is called fluid friction or drag. The amount of Frictional force by a fluid on an object depends upon the following:

The speed of the object with respect to the fluid.

The nature of the fluid, its viscosity or its tendency to resist the flow.

The shape of the object.

Fluid Friction comprises Internal and External Friction:

Fluids comprise of internal Friction that occurs between the molecules of a liquid as they are also in motion. The viscosity of a liquid, therefore, depends upon the internal Friction.

An external Friction in fluids is the force exerted by the fluid on the object that flows through it.

As an object travels in a fluid it loses its energy in order to overcome the fluid Friction. Hence, things that can easily flow in fluids have special shapes.

For instance, ships and boats have a particular shape that allows them to resist fluid Friction.

Birds and aeroplanes have a specific shape that allows them to fly in the air.

Fishes also have a specific shape such as a tail and fins that allow them to swim continuously in water and even prevent the loss of energy due to fluid Friction.

Not only this, all the vehicles are designed in a way that they can resist the fluid Friction because air is present everywhere.

Figure 12 Objects can resist Fluid Friction because of their special Shape

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NCERT Solutions for Class 8 Science Chapter 12 - Friction
NCERT Solutions

NCERT Solutions for Class 8 Science Chapter 12 - Free PDF Download

Introduction.

The study of Science is composed of fascinating and enthralling discoveries. The concept of Friction is best described in NCERT Solutions Class 8 Science Chapter 12 by Vedantu. Class 8 Science Chapter 12 NCERT Solutions is a great platform that provides the fundamentals of the chapter and accurate answers to complex numerical questions. NCERT Solutions Science Chapter 12 is what students require to ace their exams. Students are free to explore and visualise the concept by using NCERT Solutions for Class 8th Science Chapter 12.

Subjects like Science, Maths, and English will become easy to study if you have access to NCERT Solution for Class 8 Science , Maths solutions and solutions of other subjects. You can also download NCERT Solutions for Class 8 Maths to help you to revise the complete syllabus and score more marks in your examinations.

Important Topics for Class 8 Science Chapter 12

The Topic Friction is given with all the subtopics that are included in the syllabus of NCERT Class 8 Science Chapter 12.

Important Points

Some very basic information related to friction are provided below.

The definition of friction states that friction is a type of force that opposes the relative motion between two surfaces in contact. Friction acts on both surfaces.

Factors that affect Friction are the nature of surfaces in contact and the state of smoothness or roughness of those surfaces.

Friction is less for smooth surfaces and is independent of the area of contact.

Static friction is the force that is required to overcome friction the instant an object starts moving from rest.

Sliding friction is less than static friction.

Friction is responsible for walking, gripping, writing, transmitting energy and the wear and tear of various parts of machines.

Class 8 Science Chapter 12 Friction discusses the impacts and factors affecting friction. The chapter describes friction as the resistance that every item encounters when it moves across or through a surface or another medium. Without frictional force, an item would either not start moving or, if it was already moving, would not stop. All of these questions have been answered in the NCERT solutions PDF. The specialists who have a thorough understanding of the material have created the NCERT Solutions for Class 8 History and Social Science.

After finishing answering the questions in the textbook, students can consult these answers. It is highly recommended to consult the assigned textbook of the topic when studying for a test. All of the questions from the Class 8 Science Chapter 12 Friction NCERT textbook are included in the NCERT Solutions for Class 8 Science Chapter 12. Download the PDF to ace your preparations.

Some of the Major Topics Covered under Class 8 Science Chapter 12 - Friction

The following are some of the important topics that are covered in Chapter 12 of the Class 8 curriculum.

What Are the Causes of Friction?

Factors Affecting Friction

Types of Friction

Advantages of Friction

Disadvantages of Friction

Access NCERT Solutions for Science Class 8 Chapter 12 – Friction

Friction opposes the ________ between the surfaces in contact with each other.

Ans: Motion

Friction depends on the _________ of surfaces.

Ans: Nature

Friction produces _________.

Sprinkling of powder on the carrom board ________ friction.

Ans: Reduce

Sliding friction is ________ than the static friction.

Ans: Lesser

rolling, static, sliding

rolling, sliding, static

static, sliding, rolling

sliding, static, rolling

Ans: (c) Static, sliding, rolling.

Static Friction: When we move an object which is at rest.

Sliding Friction: Acts on a body when it is moving.

Rolling Friction: Here the area of contact is smallest when compared to static and sliding friction.

a. Wet marble floor, dry marble floor, newspaper and towel. b. Newspaper, towel, dry marble floor, wet marble floor. c. Towel, newspaper, dry marble floor, wet marble floor d. Wet marble floor, dry marble floor, towel, newspaper

Ans : (a) Wet marble floor, dry marble floor, newspaper and towel.

Friction will be more if the surface is rough and it will be less if the surface is smooth. Hence, wet marble floor, dry marble floor, newspaper and towel is the correct sequence of these surfaces when arranged according to the increase in the force of friction acting on the car.

Ans: When a book slides down a table, frictional force always acts always opposite to the direction of motion and along the incline.

Force of friction will always be parallel to the surfaces in contact.

Ans: It would be difficult to walk on the floor when soapy water falls on the floor then the friction reduces therefore the chances to slip increases, as a result it becomes difficult to walk.

When there is no soapy water then there will be interlocking between the foot and the ground.

When soap water spills the interlocking gets spoilt as a result friction reduces.

Ans: Spikes present on the shoes make the surface of the shoes rough. This increases the friction. As friction increases, the grip on the ground increases. This makes it easier for them to walk or run.

Friction is directly proportional to mass. Heavier an object more force to be applied to move it.

Heavier box will press the floor surface harder as compared to the lighter box.

The two surfaces are pressed harder against each other, so the force required to overcome the interlocking is more in case of the heavier box.

So Seema has to apply more force as compared to Iqbal.

Ans : During sliding, contact points do not get enough time to get interlocked properly. Friction forces come into play when irregularities present in the surface of the two objects in contact get interlocked with each other. When an object is in motion, the sliding friction is smaller than the static friction as the interlocking during motion is very small. Thus, sliding friction is less than static friction.

Friction is a friend in the below ways :

It helps us to walk.

It helps us to hold things.

It helps in grinding.

It helps in construction purposes.

It makes matchstick ignition possible.

Friction as a foe in the below ways:

It opposes motion.

It produces a lot of heat which results in wastage of energy.

It brings about wear and tear of machinery parts.

It leads to the application of more power in machines.

It produces noise in the machines.

Ans: Special shapes experience less fluid friction therefore can move easily through fluids. When an object moves in fluid, fluid friction opposes the motion. So, to reduce the friction between object and fluids, the object is given a special shape known as streamlined shape.

An aeroplane is a good example for this. The air exerts some friction when the aeroplane moves through the air. This will be opposed by the motion of the aeroplane. In order to overcome this friction, the aeroplane has to apply a lot of force. This force is in turn a waste of energy. So, it is necessary to design the shape of the aeroplane in such a way that it experiences less fluid friction.

NCERT Solutions Class 8 Science Chapter 12 - Free PDF Download

Downloading NCERT Solutions for Class 8 Science Chapter 12 Friction PDF from the website and app is easy. The methodical approach to strengthening the foundation of the chapter guarantees the success of any student in their board exams. NCERT Solutions Class 8 Science Chapter 12 provides answers that help in mastering the concepts, and formulae and solving numerical problems curated by our subject experts. A student can breeze through their exam revision with ease. Chapter 12 Friction Class 8 NCERT Solutions are provided as a step-by-step guide for a student of any calibre.

NCERT Solutions for Class 8 Science Chapters

Chapter 12 - Friction

NCERT Class 8 Chapter 12 Friction is part of the Physics of CBSE Science textbook. It is the primary source for this topic. The term ‘friction’ is best described along with its factors and formulas in a simplified format. Additionally, the student is provided with diagrams and different schematics to understand its applications and purpose in our world. The terminology, illustrations and numerical problems are written in a simple step-by-step format to establish a strong foundation of the topic. Our subject experts have prepared these NCERT Solutions to provide an overall knowledge base for the chapter.

Class 8 Science Chapter-Wise Marks Weightage

Class 8th Science Chapter 12 has a weightage of 20 marks. This chapter is important from an exam point of view. Basic questions and complex numericals keep repeating in the Board exams from this subject. Hence, preparing from these study materials makes students score better.

Here is more detail about the contents of Chapter 12 Friction Class 8:

Why are NCERT Solutions for Class 8 Science Chapter 12 Important?

The solutions are provided topic-wise along with brief descriptions, simplified illustrations and detailed answers to numerical problems.

NCERT Solutions for Class 8 Science Chapter 12 Friction are prepared by a team of experts who make learning simple and fun.

Our simplified answers provide an easy understanding and a valuable learning experience for smooth exam revision.

NCERT Science (Physics) Class 8 Chapter 12 comes with important points and engaging activities to learn the concept practically.

Our syllabus helps you score better and aid you with complete revision.

Apart from that, these solutions contain all the solved questions/answers and exercises of the chapter.

Chapter wise NCERT Solutions for Class 8 Science

Chapter 1 - Crop Production and Management

Chapter 2 - Microorganisms: Friend and Foe

Chapter 3 - Synthetic Fibres and Plastics

Chapter 4 - Materials: Metals and Non-Metals

Chapter 5 - Coal and Petroleum

Chapter 6 - Combustion and Flame

Chapter 7 - Conservation of Plants and Animals

Chapter 8 - Cell - Structure and Functions

Chapter 9 - Reproduction in Animals

Chapter 10 - Reaching The Age of Adolescence

Chapter 11 - Force and Pressure

Chapter 13 - Sound

Chapter 14 - Chemical Effects of Electric Current

Chapter 15 - Some Natural Phenomena

Chapter 16 - Light

Chapter 17 - Stars and The Solar System

Chapter 18 - Pollution of Air and Water

Along with this, students can also view additional study materials provided by Vedantu, for Class 8:

NCERT Exemplar for class 8 Science Chapter 12

CBSE Revision Notes for class 8 Science Chapter 12

Benefits of Studying from Vedantu’s NCERT Solutions for Class 8 Science Chapter 12 Friction

The following are some of the key benefits of practising the NCERT Solutions for Class 8 Science Chapter 12 Friction

NCERT solutions are curated by experts with a primary focus to cover all the important topics.

The solutions are in a simple, precise and easy-to-understand format.

The solutions are accurate and follow the CBSE pattern of answering questions.

The subject matter experts have provided well-explained solutions keeping the intellectual capacities of all students in mind so that it would help in better understanding the concepts for all.

Concepts are followed by examples for a better understanding of the theories.

Vedantu's NCERT Solutions for Class 8 Science Chapter 12 - "Friction" provide comprehensive insights into the fascinating world of friction. These solutions cover the fundamental concepts and principles related to frictional forces, making it easier for students to understand the role of friction in everyday life. With a focus on clarity and accuracy, Vedantu's commitment to education is evident, offering accessible and quality resources for students. These solutions not only enhance scientific comprehension but also empower students to appreciate the significance of friction in various applications, from transportation to industrial processes. Vedantu's dedication to promoting scientific literacy and excellence is commendable, making these solutions an essential part of students' science education.

FAQs on NCERT Solutions for Class 8 Science Chapter 12 - Friction

1. Explain the Concept of Sliding Friction and its Relation to the Mechanism of Static Friction.

Frictional forces play a key role when irregularities on the surface of an object are discovered even if the surface is smooth. This is observed when the irregularities of two surfaces come into contact with each other and get interlocked. Sliding friction or kinetic friction is a contact force that resists the sliding motion of two objects. Static friction is the force of friction observed on a stationary object. It is larger than sliding friction as the interlocking mechanism is very small.

2. What are Some Examples of Friction Observed in Our Daily Lives?

Friction is both a friend and a foe. Some instances where we see friction in action are as follows:

Walking or running up or down a hill.

The wear and tear of shoes after vigorous activity.

The contact between the pen and the paper and the motion of the pen while writing.

The damages are caused by continuous exposure to heat in heavy-duty machines as they are continuously run. Therefore, lubricants are used to decrease the wear and tear of these machines.

Rubbing our hands together to generate heat

3. What are the various types of friction? Explain.

There are four types of Friction:

Static Friction - The frictional force, which acts in between two surfaces, when both are at rest with respect to each other.

Sliding Friction - The frictional force acts between two surfaces that are sliding with respect to each other.

Rolling Friction - The resisting force acts between the motion of anybody that performs rolling motion.

Fluid Friction - When the frictional force acts between two layers of liquid flowing with respect to each other.

4. What is the cause of friction?

A surface is not completely smooth and always has some irregularities, which become the main cause of the force of friction that comes into play when two surfaces come in contact with each other. If we go into the details, the roughness of the surface and molecular adhesion of surface molecules are the main reason behind the friction of any surface. So, the surfaces which have more roughness tend to have more friction.

5. What is friction?

The force which is resistive in nature and comes into play due to the relative motion between two surfaces is known as friction. The direction of the force is always opposite to the direction of motion and it tends to oppose the motion of the body. It comes into play due to the irregularities in surfaces and molecular adhesion properties of the surfaces of the objects. It is mainly of 4 types.

6. List out the topics included in Chapter 12 of NCERT Solutions for Class 8 Science.

Following are the topics included in Chapter 12 of NCERT Solutions for Class 8 Science :

Force of Friction

It has one short answer

Factors affecting friction

It has two MCQs and one short answer

Friction: A Necessary Evil

It has one long answer

Increasing and Reducing Friction

It has one short and one long answer

Wheels Reduce Friction

Fluid Friction

It has two MCQs and one short answer

Students can download the PDF file of NCERT Solutions free of cost to study offline.

7. What is frictional force covered in Chapter 12 of NCERT Solutions for Class 8 Science?

The frictional force is the force that acts between two surfaces when there occurs any relative motion between them. It resists the motion between the surfaces. It is caused due to irregularities in the surface and the adhesion of molecules of one surface with another. The force of friction is also necessary for the motion and thus is also known as a necessary evil. There are four types of frictional forces, static, sliding, rolling and fluid. To know more about Chapter 12 Class 8 Science, visit the Vedantu app and the website (vedantu.com).

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NCERT Solutions for Class 8 Science Chapter 12 Friction

NCERT Solutions Class 8 Science Chapter 12 – Access And Download Free PDF

NCERT solutions for class 8 science chapter 12 Friction: If you are a CBSE student in class 8, you may be one of those looking for solutions for NCERT class 8 chapter 12 friction. This is an important chapter for class 8 students. To score good marks, knowing the CBSE NCERT solutions for class 8 science chapter 12 friction would be an advantage. In this chapter, you will get to know the topics like forces of friction, factors affecting friction, why friction is necessary, what is increasing and decreasing friction, how wheels reduce friction, static friction, ball bearings, fluid friction, use of lubricants and more.

NCERT solutions for class 8 science chapter 12 friction: Solved Exercise Questions

Ncert solutions for class 8 science- chapter-wise, ncert solutions for class 8: subject-wise, friction class 8 ncert science chapter: topics, how to use chapter-wise ncert solutions, key features of ncert solution for class 8 science.

You can also check the detailed NCERT solutions for class 8 science chapter 12 friction on this page. Other NCERT solutions for class 8 are also available to understand how to derive the answers to the various questions asked in each chapter and each exercise. This, in turn, will help in performing better in the exams and scoring very good marks. Now just that, a good understanding of the NCERT solutions for subjects science or maths will further aid in higher classes and entrance exams like JEE Main and NEET which are for engineering and medical courses respectively.

**As per the CBSE Syllabus for the academic year 2023-24, this chapter has undergone a renumbering and is now designated as Chapter 8.

Q1. Fill in the blanks.

(a) Friction opposes the _____________ between the surfaces in contact with each other. (b) Friction depends on the _____________ of surfaces. (c) Friction produces __________. (d) Sprinkling of powder on the carrom board ________ friction. (e) Sliding friction is ___________ than the static friction.

(a) Friction opposes the motion between the surfaces in contact with each other. (b) Friction depends on the nature of surfaces. (c) Friction produces heat . (d) Sprinkling of powder on the carrom board reduces friction. (e) Sliding friction is less than the static friction.

Q2. Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement.

(a) rolling, static, sliding (b) rolling, sliding, static (c) static, sliding, rolling (d) sliding, static, rolling

Static friction > sliding friction > rolling friction.

Q3. Alida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be

(a) wet marble floor, dry marble floor, newspaper and towel. (b) newspaper, towel, dry marble floor, wet marble floor. (c) towel, newspaper, dry marble floor, wet marble floor. (d) wet marble floor, dry marble floor, towel, newspaper

The force of friction acting on the car on different surfaces in increasing order will be wet marble floor, dry marble floor, newspaper and towel. Therefore (a) is the correct answer.

Q4. Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

The frictional force will be opposite to the direction of motion

Q5. You spill a bucket of soapy water on a marble floor accidentally. Would it make it easier or more difficult for you to walk on the floor? Why?

It would make it more difficult for us to walk on the marble floor since the frictional force would further decrease and thus our grip on the floor while walking would become even lesser.

Q6. Explain why sportsmen use shoes with spikes.

Sportsmen use shoes with spikes to increase the grip between their feet and the ground by increasing the friction with the help of spikes. This aids them while running on the ground.

Q7. Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

Seema would have to apply a larger force as she would have to overcome a greater frictional force. The frictional force between two surfaces exists due to the interlocking of the irregularities on the surface. The magnitude of this frictional force depends on how tight this interlocking is which in this case depends on the weight of the boxes which is more in the case of Seema.

Q8. Explain why sliding friction is less than static friction.

Sliding friction is less than static friction as the frictional force between two surfaces depends on the interlocking between the irregularities on the surfaces. This interlocking in case of sliding decreases as the contact points does not get enough time to interlock properly thus reducing the frictional force.

Q9. Give examples to show that friction is both a friend and a foe.

Friction acting as a friend:

(a) It aids us to walk and cars to move on the roads.

(b)Fire can be ignited using friction.

Friction acting as a foe:

(a) It causes the efficiency of engines to decrease and also damages machinery.

(b) Friction causes the soles of shoes and tires to wear off.

Q10. Explain why objects moving in fluids must have special shapes.

When an object is moving through a liquid there is an opposing force offered by the liquid against the motion of the object. To reduce this opposing force objects must have special shapes.

The subject matter experts at Careers360 have created a comprehensive class 8 science chapter 12 question answer that is designed to help students understand the concepts easily. The solutions are provided in a step-by-step format with diagrams, making it easier for students to follow along. The PDF version of the NCERT class 8 science chapter 12 solution can be downloaded by students for their convenience.

Additionally, the solutions for science class 8 chapter 12 cover a variety of question types, including fill-in-the-blanks, correct arrangement, and short answer type questions, giving students a well-rounded understanding of the chapter. Students can use these solutions to prepare for exams, revise the chapter, or simply deepen their understanding of the subject.

NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 8 Science

Class 8 Science Chapter 12 NCERT Solutions: Important Formulas and Diagrams

Friction is a force that opposes the relative motion or attempts to oppose the motion between two objects in contact.

It always acts in the direction opposite to the direction of motion or attempted motion.

Types of Friction

Static Friction: This is the friction that opposes the initial motion of an object at rest. It's the maximum force of friction that can be applied before motion starts.

Kinetic Friction: Once an object is in motion, this friction opposes its motion.

Rolling Friction: Occurs when one object rolls over another. It's generally less than kinetic friction.

Coefficient of Friction (μ)

It's a measure of the frictional properties between two materials.

The formula for frictional force: Frictional force (F) = Coefficient of friction (μ) × Normal force (N)

Coefficient of friction = force of friction / normal force

Methods to Reduce Friction

Lubrication: Adding a lubricant (like oil or grease) between surfaces reduces friction.

Smoothing: Making surfaces smoother can reduce friction.

Ball bearings: These reduce friction in rotating parts.

Reducing Friction in Daily Life

Lubricating moving parts of machines.

Using ball bearings in machinery.

Polishing or smoothing surfaces.

Force of friction
Factors affecting friction
Friction - a necessary evil
Increasing and reducing friction
Wheels reduce friction
Fluid friction
Ball Bearing
Fluid Friction
Interlocking
Rolling Friction
Sliding Friction
Static Friction

Now that the NCERT solutions for class 8 science chapter 12 friction are done on this page, it's time to move to other chapters and topics as well. The list is given above. All you need to do is click on the given link and the NCERT chapter with solutions to all exercises will be displayed. Use them to understand and solve to score more marks in your exam.

Comprehensive Coverage: The friction class 8 solutions provide comprehensive coverage of the topic, addressing various aspects of friction, its causes, effects, and practical applications.

Detailed Explanations: The friction class 8 NCERT Solutions offer detailed and easy-to-understand explanations for all the questions and concepts presented in the chapter. This helps students grasp the material effectively.

Real-Life Examples: The class 8 science chapter 12 NCERT solutions include real-life examples and scenarios to illustrate the concepts of friction, making it easier for students to relate to and understand the subject matter.

Variety of Question Types: The class 8 friction NCERT solutions cover various question types, including multiple-choice questions, short answer questions, long answer questions, and numerical problems. This diversity allows students to practice different problem-solving techniques.

Practical Applications: Many questions are designed to highlight the practical applications of friction in everyday life, helping students see the relevance of the topic beyond the classroom.

Step-by-Step Solutions: For friction class 8 questions and answers, step-by-step solutions are provided. These solutions guide students through the problem-solving process, enabling them to understand the methodology.

Conceptual Clarity: The science chapter 12 class 8 aims to enhance students' conceptual clarity by breaking down complex ideas into simple, understandable explanations.

Assessment and Practice: The questions and solutions serve as valuable tools for self-assessment and practice. Students can use them to test their understanding of the chapter and prepare for exams.

Exam Orientation: Many questions are designed with a focus on exam preparation, aligning with the CBSE curriculum and exam pattern.

Critical Thinking: Some questions encourage critical thinking, requiring students to analyze situations, make predictions, and draw conclusions based on their knowledge of friction.

Comprehensive Answers: The class 8 science ch 12 question answer provided for each question are comprehensive and well-explained, ensuring that students not only know the correct answer but also understand the underlying concepts.

Also Check NCERT Books and NCERT Syllabus here:

NCERT Books Class 8 Science
NCERT Syllabus Class 8 Science
NCERT Books Class 8
NCERT Syllabus Class 8

Frequently Asked Question (FAQs)

Yes, friction, force, motion and pressure are important topics that will be studied in Class 9 NCERT Science Syllabus and also in Class 11 NCERT Physics book

Friction opposes the motion between the surfaces in contact with each other. If there is no frictional force we wont be able to walk.

The following topics are covered in the chapter friction:

Force of friction

Factors affecting friction

Friction - a necessary evil

Increasing and reducing friction

Wheels reduce friction

Fluid friction

Ball Bearing

Drag

Fluid Friction

Friction

Interlocking

Lubricants

Rolling Friction

Sliding Friction

Static Friction

μ represents the coefficient of friction between two surfaces.

The value of the coefficient of friction (μ) varies depending on the materials of the surfaces in contact and other factors such as temperature and pressure. It can range from 0 to 1 or even higher.

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Friction Class 8 Science Extra Questions and Answers

Friction Class 8 Science Chapter 12 Extra Questions and Answers are provided here. We prepared these extra questions based on the latest NCERT Class 8 Science Book. CBSE Class 8 Science Chapter 12 Friction Extra Questions will help you to properly understand a particular concept of the chapter.

Class 8 Science Chapter 12 Friction Extra Questions

Very short answer type question.

Question 1: Which force helps things to move and stop?

Answer: Frictional force

Question 2: What enables a ladder to lean against the wall?

Answer: Friction

Question 3: Name two common lubricants.

Answer: Oil and Grease

Question 4: Mention one simple method of reducing friction between two surfaces.

Answer: Lubrication

Question 5: What is drag?

Answer: The frictional force exerted by fluids is also called drag.

Question 6: Which type of surface produces less friction?

Answer: Smooth surface produces less friction.

Question 7: Why the soles of our shoes wear out gradually?

Answer: The soles of shoes wear out gradually due to friction.

Question 8: Which type of surface produces more friction?

Answer: Rough surface produces more friction.

Question 9: Why ball bearings are used in machines? Or What is the purpose of using ball bearing in machine?

Answer: Ball bearings reduce friction. Thus, they are used in machines.

Question 10: Write any two machines in which ball bearings are used.

Answer: Ceiling fans and Bicycles

Question 11: What makes the steps of foot over-bridges at Railway Stations to wear out slowly?

Question 12: What are lubricants?

Answer: The substances which reduce friction are called lubricants.

Question 13: Why do we sprinkle fine powder on the carrom board?

Answer: Powder is sprinkled on the carrom board to reduce friction.

Question 14: Name the force responsible for wearing out of car tyres.

Answer: Frictional force is responsible the wearing of car tyres.

Question 15: What is the direction of force of friction acting on a moving object? Or What is the direction of force of friction?

Answer: The force of friction always opposes the applied force.

Question 16: Which force always opposes motion Or What is the force that always opposes motion?

Answer: Friction force always opposes motion.

Question 17: What is done to increase friction between the tyres and road?

Answer: The tyres of the vehicle are treaded to increase friction.

Question 18: When does static friction come into play?

Answer: Static friction comes into play when we try to move an object at rest.

Question 19: When does sliding friction come into play?

Answer: Sliding friction comes into play when an object is sliding over another.

Question 20: Why is the surface of a slide polished to make it smooth?

Answer: The surface of a slide polished to make it smooth in order to reduce friction.

Question 21: Why do kabaddi players rub their hands with dry soil?

Answer: Kabaddi players rub their hands with soil for a better grip of their opponents.

Question 22: Which type of friction comes into play when a book on cylindrical pencils is moved by pushing?

Answer: Rolling friction

Question 23: Name the device which is attached to heavy luggage (such as a heavy suitcase) to move it easily by pulling.

Answer: Rollers

Question 24: Give one example from everyday life where wheels (or rollers) are used to reduce friction.

Answer: Suitcase

Question 25: Why a bicycle and a motor mechanic use grease between the moving parts of these machines?

Answer: They do so to reduce friction in order to increase efficiency.

Question 26: Why are cars, aeroplanes and rockets streamlined?

Answer: Cars, aeroplanes and rockets are streamlined to reduce the fluid friction.

Question 27: What prevents us from slipping every time we take a step forward?

Answer: Frictional force prevents us from slipping every time we take a step forward.

Question 28: Why are treads made in the surface of tyres?

Answer: The treaded tyres of cars, trucks and bulldozers provide better grip with the ground.

Question 29: What are fluids?

Answer: In science, the common name of gases and liquids is fluids.

Question 30: Name two common fluids.

Answer: Two common fluids names are air and water.

Question 31: Why do gymnasts apply a coarse substance to their hands?

Answer: Gymnasts apply some coarse substance on their hands to increase friction for better grip.

Question 32: Why is it difficult to climb up an oily or greasy pole?

Answer: An oily or greasy pole has much less friction due to which it is difficult to climb up an oily or greasy pole.

Question 33: Which device is used between the hubs and axles of bicycle wheels to reduce friction?

Answer: Ball bearing is used between hubs and the axles of ceiling fans and bicycles to reduce friction.

Short Answer Type Questions

Question 1: Why do tyres of cars wear out gradually?

Answer: The tyres of cars wear out gradually due to friction between the surface of tyres and the surface of road.

Question 2: What is static friction?

Answer: The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction.

Question 3: What is sliding friction?

Answer: The force required to keep the object moving with the same speed is a measure of sliding friction.

Question 4: What is rolling friction?

Answer: When one body rolls over the surface of another body, the resistance to its motion is called the rolling friction.

Question 5: Why is it difficult to walk on a well-polished floor?

Answer: A well-polished floor offers very less resistance. Therefore, it is difficult to walk properly on a well-polished floor.

Question 6: Why is it difficult to walk on a smooth and wet floor?

Answer: A smooth and wet floor offers very less resistance. Therefore, it is difficult to walk properly on a smooth and wet floor.

Question 7: Can we reduce friction to zero by polishing surfaces or using large amount of lubricants?

Answer: Friction can never be entirely eliminated. No surface is perfectly smooth. Some irregularities are always there.

Question 8: What happens when you rub your hands vigorously for a few seconds? Why does this happen?

Answer: If we rub our hands together for several seconds, then our hands feel warm. That warmth is caused by a force called friction.

Question 9: Explain why sportsmen use shoes with spikes.

Answer: Sportsmen use shoes with spikes because spikes increase the force of friction between the shoes and the ground and give them a better grip while running.

Question 10: Why do we slip when we step on a banana peel?

Answer: The inner side of banana peel being smooth and slippery reduces the friction between the sole of our shoes and the surface of road. Thus, we slip on it.

Question 11: Why the sole of our shoes is grooved?

Answer: The grooves are made in the soles of shoes to increase friction with the ground so that the shoes get a better grip on the floor and we can walk safely.

Question 12: Why do car wheels often spin on icy roads?

Answer: A car spins on icy road because the treads of the car can no longer maintain the proper friction to keep it moving. Due to ice, the friction reduces and the car spins.

Question 13: Why a pencil eraser loses tiny pieces of rubber each time we use it?

Answer: When we use a pencil eraser, friction between the eraser and the paper rubs off some rubber particles from the eraser. Thus, the eraser loses tiny pieces of rubber due to friction.

Question 14: Why a vehicle slows down when brakes are applied?

Answer: When brakes are applied, the brake pads press against the discs of the rotating car wheels. This produces friction between brake pads and the discs, making the wheels to slow down and ultimately stop.

Question 15: Why it is convenient to pull the luggages fitted with rollers? Or Even a child can pull attaches and other pieces of luggage fitted with rollers. Why is it so?

Answer: Rolling reduces friction. It is always easier to roll than to slide a body over another. That is the reason it is convenient to pull the luggages fitted with rollers.

Long Answer Type Questions

Question 1: What enables us to fix nails in a wall and knots to be tied?

Answer: When we hammer a nail in the wall, it is the friction between the surface of nail and wall which holds the nail tightly in the wall. Without friction, nails could not be fixed in a wall to hold things.Friction enables knots to be tied in the ropes.

Question 2: What is a spring balance?

Answer: Spring balance is a device used for measuring the force acting on an object. It consists of a coiled spring which gets stretched when a force is applied to it. Stretching of the spring is measured by a pointer moving on a graduated scale. The reading on the scale gives the magnitude of the force.

Question 3: How does a bicycle stop when its brakes are applied?

Answer: We deliberately increase friction by using brake pads in the brake system of bicycles and automobiles. When we are riding a bicycle, the brake pads do not touch the wheels. But when we press the brake lever, these pads arrest the motion of the rim due to friction. The wheel stops moving.

Question 4: When we strike a matchstick against the rough surface, it catches fire. Give reason.

Answer: When we strike a matchstick against the rough surface, then the friction between the head of the matchstick and rough surface produces heat. This heat burns the chemicals present on the head of the matchstick due to which the matchstick catches fire.

Question 5: Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

Answer: When a book slides on the writing desk, a frictional force acts between the book and the surface of the desk. The direction of frictional force on the book is opposite to the direction of its motion and acts in upward direction.

Question 6: How lubricants work?

Answer: When oil, grease or graphite is applied between the moving parts of a machine, a thin layer is formed there and moving surfaces do not directly rub against each other. Interlocking of irregularities is avoided to a great extent. Thus, Movement becomes smooth.

Question 7: Explain why the sliding friction is less than the static friction.

Answer: Friction is caused by the interlocking of irregularities in the two surfaces. When the object starts sliding, the contact points on its surface do not get enough time to lock into the contact points on the floor. So, the sliding friction is slightly smaller than the static friction and we find it somewhat easier to move the object already in motion than to get it started.

Question 8: Why will a pencil write on a paper, but not on a glass?

Answer: We are able to write on a paper because there is friction between the tip of the pencil and paper. We are not able to write on a glass because the glass surface is very smooth due to which friction between the tip of the pencil and glass surface is less. This friction is not enough to rub off black graphite particles from the tip of pencil.

Question 9: When we try to push a very heavy box kept on ground, it does not move at all. Which force is preventing this box to move forward? Where does this force act?

Answer: When we push a very heavy box kept on the ground, it does not move at all because frictional force balances the force that we apply. So, there is no net movement of this box. It acts in a direction opposite to the force we apply.

Question 10: Explain why objects moving in fluids must have special shapes.

Answer: Fluids exert force of friction on objects in motion through them. The frictional force on an object in a fluid depends on its speed with respect to the fluid. The frictional force also depends on the shape of the object and the nature of the fluid. It is obvious that when objects move through fluids, they have to overcome friction acting on them. In this process they lose energy. Efforts are, therefore, made to minimize friction.

Question 11: Give examples to show that friction is both a friend and a foe.

Answer: Advantages of friction:

Friction enables us to walk.
Friction enables us to write with pen or pencil.

Disadvantages of friction:

Friction wears away the soles of our shoes.
The tyres of vehicles wear out gradually due to friction.

Question 12: You spill a bucket of soapy water on a marble floor accidently. Would it make it easier or more difficult for you to walk on the floor? Why?

Answer: We are able to walk because of the friction present between our feet and the ground. In order to walk, we push the ground in the backward direction with our feet. The force of friction pushes it in the forward direction and allows us to walk. The force of friction between the ground and feet decreases when there is soapy water spilled on the floor. Hence, it becomes difficult to walk on the soapy floor.

Question 13: Which is easier to hold in hand: a kulhar (earthen pot) or a glass tumbler? Why?

Answer: It is easier to hold a kulhar (earthen pot) in our hand than a glass tumbler. This is because due to rough surface of kulhar, the friction between kulhar and our hand is much more which makes it easier to hold it. On the other hand, due to the smooth surface of glass tumbler, the friction between glass tumbler and hand is much less which makes it comparatively difficult to hold it.

Question 14: Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

Answer: Force of friction arises because of interlocking of irregularities on the two surfaces in contact. When a heavy object is placed on the floor, the interlocking of irregularities on the surfaces of box and floor become strong. This is because the two surfaces in contact are pressed harder. Hence, more force is required to overcome the interlocking. Thus, to push the heavier box, Seema has to apply a greater force than Iqbal.

Question 15: How do rough and smooth surfaces affect friction? Or Why do smooth surfaces have less friction? Or Why do smooth surfaces have less friction than non-smooth surfaces? Or Why does a rough surface have greater friction than a smooth surface? Or Friction depends on the nature of two surfaces in contact. Explain. Or Is the friction the same for all the surfaces? Does it depend on the smoothness of the surfaces?

Answer: Friction is caused by the irregularities on the two surfaces in contact. Even those surfaces which appear very smooth have a large number of minute irregularities on them. Irregularities on the two surfaces lock into one another. When we attempt to move any surface, we have to apply a force to overcome interlocking. On rough surfaces, there are a larger number of irregularities. So the force of friction is greater if a rough surface is involved.

At Study Path, you can also learn more about Class 8 Science Chapter 12 Friction by accessing the free exhaustive list of study materials and resources related to the chapter such as NCERT Solutions, Notes, Important Questions, and MCQ.

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NCERT Revision Notes Chapter 12 Friction Class 8 Science

• Introduction

→ Causes of Friction

→ Nature of surfaces of Friction

→ Friction when object is pressed hard

→ Friction according to mass of object

→ Examples where friction is useful

→ Examples where friction is harmful

• Rolling Friction

• Sliding Friction

• Fluid Friction

→ The vehicles, any object, moving over the surface of another object slows down due to the force of friction applied on it.

→ It is an opposing force that acts between surfaces in contact moving with respect to each other.

→ It always opposes relative motion between two surfaces.

Cause of friction

→ Friction is cause by the irregularities on the two surfaces in contact.

→ We are able to walk because of the force of friction.

Nature of surfaces for Friction

Smooth surfaces: less friction

Rough surfaces: greater friction

Friction when object is pressed hard

Greater pressing force means Greater friction.

Friction according to mass of object

Greater mass: Greater friction

Sliding friction < Static friction

Rolling friction < Sliding friction

Examples where friction is useful

(i) Walking

(ii) Handling any object

(iii) Rolling motion of ball or wheel

Examples where friction is harmful

(i) Energy dissipation of engine due to friction between surfaces in motion.

(ii) More energy is lost in pulling or pushing an object in rough surfaces.

(iii) Wear and tear of shoe soles and tyres.

(iv) Lubrication: Powder on carom board, oil in machine

(v) Wheel: Wheels reduce friction (because rolling friction < sliding friction).

(vi) Shoe soles and tires are threaded to increase friction for a better grip.

(vii) Fluid friction is minimised by giving suitable shapes to vehicles moving through fluids.

→ When a body rolls over the surface of another body, the resistance to its motion is called rolling friction.

→ When a body slides over the surface of another body, the resistance to its motion is called sliding friction.

• Rolling friction < Sliding friction

→ Ball bearings change sliding friction into rolling friction.

→ Fluid friction is minimised by giving suitable shapes to vehicles moving through fluids.

• Fluid friction is also called drag.

→ Friction force depends upon the speed of the object with respect to the fluid.

→ Friction force depends upon the shape of the and nature of the fluid.

NCERT Solutions for Chapter 4 The Age of Industrialisation Class 10 History

Related chapters.

Crop Production and Management
Microorganisms : Friend and Foe
Synthetic Fibres and Plastics
Materials: Metals and Non-Metals
Coal and Petroleum

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Notes of Ch 12 Friction| Class 8th Science

Study material and notes of ch 12 friction class 8th science.

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NCERT Solutions for Class 8 Science Chapter 12

Science is enthralling. Science is a method of learning what exists in the universe and how it functions today, functioned in the past, and will do so in the future. Scientists are inspired by the pleasure of uncovering or discovering something previously unknown. Science exists all around us. The fact that you can read this text and live simultaneously is Science.

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Friction is the resistance that any item encounters when travelling across or through a surface or medium. NCERT Class 8 Science Chapter 12 is Friction. It teaches that in the absence of frictional force, an object’s movement would either not begin or, if already underway, would not come to a complete halt. The chapter discusses the numerous forms of friction we observe daily.

Extramarks NCERT solutions provide detailed and authentic answers to all the textbook questions. Through those, the students can understand, remember and retain answers to NCERT questions and thus, perform well in exams.

The experts have prepared Class 8 Science Chapter 12 Solution. Going through the NCERT Solutions of a chapter is essential for students to get better results in the examinations. Hence, Extramarks provides Class 8 Science Chapter 12 NCERT Solutions of the chapter Friction. These solutions not only help to learn the concepts but also to retain them.

Extramarks can be a one-stop solution for all students’ problems. Apart from NCERT Solutions for Class 8 Science Chapter 12- Friction, NCERT Solutions, Additional Questions, Sample Papers, Revision Notes, CBSE Previous year question papers, and a lot more can be found on the Extramarks website.

Key Topics Covered in NCERT Solutions for Class 8 Science Chapter 12

Making it easier for the students and listing below the key topics that are covered in NCERT Solutions for Class 8 Science Chapter 12:

Let us look at Extramarks in-depth information on each subtopic in NCERT Solutions for Class 8 Science Chapter 12- Friction.

What is Friction?

A ball thrown on the floor moves all over. However, if no opposite force is exerted in the direction of motion, the ball should continue to roll as per Newton’s first law, but this does not happen. In place of it, the ball comes to a halt after a set distance, indicating that an opposite force is operating on it and causes it to stop. Friction is what we term this force as.

Extramarks’ NCERT Solutions for Class 8 Science Chapter 12 defines friction as the resistance provided by the surfaces in contact as they move past one another.

Relative Motion

A relative motion occurs when one thing moves in relation to another.

What causes friction?

Due to uneven surfaces of the objects coming into contact, a frictional force is created. This frictional force interlocks micro-level irregularities between the two characters and ploughs harder surfaces into smoother surfaces. As a result, the frictional force is the opposite of the force of motion and causes a speed reduction, and eventually, the object stops its state of motion.

Surface Irregularities

If zoomed in to a microscopic level, all surfaces have hills and valleys that interlock when they move or brush against one another.
Surface irregularities or roughness refers to the unevenness of the surface.
Surface imperfections are bigger on rough surfaces and smaller on smoother surfaces.

Adhesive Forces

When two surfaces come into contact, they begin to create bonds and adhere to one another. Adhesion is the term for this phenomenon.
When we try to move things stacked on top of one another, we are breaking or overcoming adhesive forces.

Ploughing Effect

When surfaces are soft or easily flexible, they distort when they come into touch with another item. For example, when a heavy object is put on a carpet, the distortion of the shape creates the appearance of a valley.
Ploughing is the term for the action of surfaces sinking into one other.

Extramarks NCERT Solutions for Class 8 Science Chapter 12 explains friction causes in the above points. Refer to Extramarks for more details on such information.

Factors affecting friction

Multiple factors affect Friction; Extramarks NCERT Solutions for Class 8 Science Chapter 12 states the following:

Nature of Surface in Contact

Friction is determined by how strongly the two surfaces are forced together; as more surfaces come into contact, more bonds are created, and more bonds are broken, the friction increases.
Friction is increased only when the usual response force (perfectly perpendicular) to the two surfaces is applied.

Calculating Frictional Force using a Spring balance

We can discover the frictional forces that various materials resist using a spring balance.
In comparison to stainless steel, sandpaper offers a greater reading.

Polishing surfaces in contact to change friction

Surface polishing removes imperfections and hence smooths the surface.
Friction is reduced.

Normal Reaction Force

The typical reaction force is an applied force perpendicular to the surfaces in contact.
The frictional force is increased.

Types of Friction

Extramarks NCERT Solutions for Class 8 Science Chapter 12 explains different types of friction as follows:

Static Friction

It is the force of friction operating on a body when it is at rest. This force is always equal to and opposing the object’s applied force. Limiting friction is the force that acts when the body is just at the point of slipping on the surface.

Sliding Friction

The force that resists sliding motion between two surfaces in touch, is called friction. The sliding friction is usually less than the static friction.

Rolling Friction

When one body rolls over the other, friction is created between the two surfaces. However, the frictional force of rolling is generally less than that of sliding.

Kinetic Friction

Kinetic friction describes the friction that occurs when things are in motion.

Friction- Both Friend and Enemy

Extramarks NCERT Solutions for Class 8 Science Chapter 12 explains that friction has benefits, so it is seen as a friend, but it also has drawbacks, so it is regarded as an enemy. Friction may be beneficial or detrimental, depending on the situation. As a result, it is an unavoidable evil.

Advantages of Friction

NCERT Solutions for Class 8 Science Chapter 12 by Extramarks gives you some advantages of friction as follows:

We can write on paper because of the friction between the pen and the paper.
Standing, walking, and running are all made possible by friction between our feet and the earth.
The friction between the road surface and our cars’ tyres allows our vehicles to go along the road without sliding.

Disadvantages of Friction

NCERT Solutions for Class 8 Science Chapter 12 by Extramarks gives you some disadvantages of friction as follows:

As their motion is resisted, moving things tend to stop or slow down due to friction.
Friction generates heat, which leads to energy waste in machinery.
Over time, friction is responsible for the wear and tear of moving components in machinery, shoe bottoms, and road tyres.

How does friction produce heat?

It is because friction involves breaking bonds, which causes particles to vibrate, increasing kinetic energy and heat.

How do you increase and reduce friction?

Ways to Increase Friction:

By firmly pushing the surfaces together, we may increase friction. For example, when we apply brakes to a bicycle or automobile, the brake pads are forced against a moving element of the wheel, resulting in increased friction force.
The roughness of the surfaces that come into contact can also be enhanced to create friction. Threading shoes and tyres, for example, is done to improve friction, which allows them to travel over the road without slipping.

Ways to Decrease Friction:

By polishing the surfaces in contact, the frictional force operating between the sliding surfaces of two objects can be minimised.
Oil, grease, graphite, or any other lubricant can minimise sliding friction between moving components of vehicles and machines. This is because the frictional force of rolling is generally less than that of sliding. As a result, sliding friction is often replaced with rolling friction by employing rollers, such as ball bearings between the hub and axles in machine and vehicle moving components.
As a result, wheels are utilised in luggage and school backpacks for children to decrease friction.

Extramarks NCERT Solutions for Class 8 Science Chapter 12 explains how to Increase and Decrease friction in the above points. Extramarks are like a bundle of quality study material. Refer to the Extramarks website to gain more information.

What is Drag Force?

Drag is a force particular only to liquids and is the term used for their frictional force.

The drag force on an item is determined by its speed and the form of its body, and the fluid’s composition.

Due to their streamlined structure, aircraft, boats, fish, and birds can travel through fluids, reducing friction and avoiding energy waste.

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Q.1 Fill in the blanks.

Q.2 Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. Their arrangements are given below. Choose the correct arrangement.

(a) rolling, static, sliding (b) rolling, sliding, static (c) static, sliding, rolling (d) sliding, static, rolling

The correct option is (c).

Explanation: The force of friction acts due to irregularities between two surfaces. Static friction acts when an object is moved from rest. Sliding friction comes into play when an object slides over the surface of another object. In sliding friction, the time given for interlocking is very less. Hence, interlocking is not strong. Therefore, less force is required to overcome this interlocking. Due to this, sliding friction is less than static friction. Also, the area of contact in case of rolling friction is smallest as compared to static or sliding friction. This area of contact changes gradually because of rolling. Thus, rolling friction is lesser than both static and sliding friction. So, the correct sequence is – static, sliding, rolling.

Q.3 Alida runs her toy car on dry marble floor, wet marble floor, newspaper and towel spread on the floor. The force of friction acting on the car on different surfaces in increasing order will be

The correct option is (a).

Explanation: Frictional force depends on the nature of surfaces in contact. The rougher the surface, the more is the friction between the surfaces in contact. According to roughness present in the given surfaces, we can arrange the force of friction acting between different surfaces as, wet marble floor, dry marble floor, newspaper and towel.

Q.4 Suppose your writing desk is tilted a little. A book kept on it starts sliding down. Show the direction of frictional force acting on it.

When the book slides on the desk, the force of friction acts between the book and the surface of the desk. The direction of frictional force is opposite to the direction of the motion of book and acts in upward direction.

Q.5 You spill a bucket of soapy water on a marble floor accidently. Would it make it easier or more difficult for you to walk on the floor? Why?

A person can walk because of the friction present between our feet and the ground. In order to walk, the person pushes the ground in the backward direction with his feet and the force of friction pushes it in the forward direction. When there is soapy water spilled on the floor, the force of friction between the ground and feet decreases. Thus, it becomes difficult to walk on the soapy floor.

Q.6 Explain why sportsmen use shoes with spikes.

A sportsman wears shoes with spikes because these shoes give him a better grip while running. Due to this, force of friction between the shoes and the ground increases.

Q.7 Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

When a heavy object is kept on the floor, the interlocking of irregularities on the surfaces of box and floor become very powerful. It is because the two surfaces in contact are pressed harder. Thus, more force is required to overcome the interlocking. Therefore, to push the heavier box, Seema has to apply a larger force than Iqbal.

Q.8 Explain why sliding friction is less than static friction.

Friction arises between two objects when irregularities present in the surfaces get interlocked with each other. In the case of sliding, the time given for interlocking is very small. Therefore, interlocking is not strong. Hence, less force is required to overcome from this interlocking. Thus, sliding friction is less than static friction.

Q.9 Give examples to show that friction is both a friend and a foe.

Friction as a Friend:

Due to friction, a person is able to walk.
Friction between the tip of a pen and a paper helps us to write.

Friction as a Foe:

Due to friction, tyres and soles of shoes wear out.
Friction between different parts of machines can generate heat. This can damage the parts of machines.

Q.10 Explain why objects moving in fluids must have special shapes.

An object moving through a fluid experiences an opposing force which tries to oppose its motion. This opposing force is also called the drag force. This force depends on the shape of the body. By giving the body a special shape, this force can be minimised. Thus, it becomes easier for the body to move through the fluid.

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Faqs (frequently asked questions), 1. what is meant by friction as per class 8th science's chapter 12.

Friction is the force that prevents one item from moving when it comes into contact with another. It happens when two surfaces come into touch with each other. For example, the mechanical advantage of a machine is dropped due to friction. When we push a heavy box stored on the floor, for example, friction occurs between the surface of the floor and the bottom of the box.

2. What exactly are Lubricants when it comes to friction?

Lubricants are chemicals that are used to minimise friction. To improve efficiency, friction should be decreased. For example, oil, grease, or graphite can minimise friction between machine moving components. Then a thin coating forms, preventing the moving surfaces from rubbing against one other. As a result, the interlocking of imperfections is avoided to the most significant degree possible, and movement is smooth. Oil-based, water-based, and silicone-based lubricants are the three primary varieties.

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Chapter 1 Crop Production and Management Case Study Question
Chapter 2 Microorganisms: Friend and Foe Case Study Question
Chapter 3 Synthetic Fibres and Plastics Case Study Question
Chapter 4 Materials: Metals and Non-Metals Case Study Question
Chapter 5 Coal and Petroleum Case Study Question
Chapter 6 Combustion and Flame Case Study Question
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Chapter 14 Chemical Effects of Electric Current Case Study Question
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Open access
Published: 21 May 2024

Association between modifiable lifestyle pattern and periodontitis: a cross-sectional study based on NHANES

Jianlin Lin 1 , 2 , 3 , 4 , 5 ,
Tao Pei 1 , 2 , 3 , 4 , 5 &
Hongyu Yang 1 , 2 , 3 , 4 , 5

BMC Oral Health volume 24 , Article number: 591 ( 2024 ) Cite this article

Metrics details

Periodontitis can be avoided with a healthy lifestyle. However, studies have only looked at one lifestyle, ignoring the connection between lifestyle patterns and periodontitis. The purpose of this study was to look at the association between modifiable lifestyle patterns and periodontitis.

Data were obtained from the National Health and Nutrition Examination Survey in 2009–2010 and 2011–2012. Smoke, drink, exercise, sleep duration, oral exams, and self-rated oral health were all lifestyle factors. The CDC/AAP classification/case definition was used to evaluate periodontitis. Drawing upon latent class analysis, distinct patterns of lifestyle were identified, with each participant exclusively affiliated with a single pattern. The association between lifestyle classes and periodontitis was then examined using ordinal logistic regression.

4686 (52%) of the total 9034 participants, with a mean age of 54.08, were women. Three lifestyle latent classes were found by fitting 2–10 models: “Class 1” (52%), " Class 2” (13%), and " Class 3” (35%). The “Class 1” displayed a prevalence of oral examination (75%), favorable self-rated oral health (92%), and engagement in physical activity (50%). The ‘Class 2’ exhibited the lowest alcohol consumption (64%) and smoking rates (73%) but the highest prevalence of physical inactivity (98%). The ‘Class 3’ showed a tendency for smoking (72%), alcohol consumption (78%), shorter sleep duration (50%), absence of oral examinations (75%), and suboptimal self-rated oral health (68%). The influencing variables for the latent classes of lifestyle were age, education, and poverty level. Periodontitis risk may rise by 24% for each additional unhealthy lifestyle practiced by participants (OR = 1.24, 95% CI: 1.18–1.31). The ‘Class 3’ (OR = 1.80, 95% CI: 1.52–2.13) had a greater risk of periodontitis compared to the ‘Class 1’.

Conclusions

Our analysis revealed that unhealthy lifestyle patterns are associated with periodontitis. These different lifestyle patterns need to be taken into account when developing public health interventions and clinical care.

Peer Review reports

Introduction

A chronic inflammatory illness affecting the tissues supporting the teeth, periodontitis is brought on by bacterial plaque [ 1 ]. Periodontitis is thought to affect 10% of people worldwide, whereas it affects approximately 42.2% of adults in the United States [ 2 ]. Diabetes, cognitive impairment, and cardiovascular and cerebrovascular illnesses are associated with periodontitis that pose a severe threat to public health globally [ 3 , 4 , 5 ]. The results of numerous research on the association between lifestyle and periodontitis suggest that decisions made regarding smoking, drinking, physical activity, and sleep duration may have an impact on how the disease manifests and advances [ 6 , 7 , 8 ]. These data collectively imply that lifestyle may have an impact on periodontitis.

High-risk populations will benefit from cost-efficient periodontitis control techniques and successful lifestyle change programs. Adults (particularly the elderly) are at a 66% higher risk of dying from bad habits and lifestyles, such as smoking, not getting enough exercise, eating poorly, and consuming too much alcohol [ 9 ]. These undesirable practices frequently occur or cluster within people. The majority of studies to date have only been concerned with modifying one unhealthy behavior [ 6 ]. Single lifestyle choices may not have much of an impact on periodontitis and may not give us enough knowledge to design successful lifestyle therapies. For example, people who drink and smoke have a higher chance of developing periodontitis than those who do not. However, there may be other groups of people who do not consume alcohol or tobacco but never get a dental examination and who also have a higher risk of developing periodontitis. Studies have examined the connection between periodontitis and lifestyle scores (i.e. the number of healthy lifestyles), however, it is impossible to determine the health advantages of people who lead various healthy lifestyles but have a score of 1, nor is it possible to use tailored interventions [ 6 ]. Consequently, the discernment of patterns associated with the integration of different lifestyles is essential for the development of all-encompassing strategies to enhance the quality of life and forestall periodontitis.

While investigations have explored the association between lifestyle choices and periodontitis, conventional clustering and factor analysis have primarily focused on continuous variables. Consequently, they fall short in elucidating the intricate associations among categorical variables, resulting in limited interpretability. Latent class analysis (LCA) offers a statistical approach adept at addressing categorical variables [ 10 ], particularly as lifestyle measures often manifest as binary variables. LCA categorizes the population into subgroups based on the probability of individuals responding to the measured variables. LCA produces good interpretability and has been used in some studies to comprehend the various lifestyle patterns. For instance, a previous study based on diet, physical activity patterns, smoking, and blood pressure control of hypertensive patients, classified their lifestyles into three risk classes: low-risk class (I), intermediate-risk class (II), and high-risk class (III), and examined the patterns in relation to sociodemographic characteristics [ 11 ]. Another Israeli study divided lifestyle into three possible categories: “healthy,” “unhealthy,” and “mixed” based on individuals’ consumption of fruits and vegetables, smoking, physical activity, sleep, and vaccination [ 12 ]. These findings suggest that lifestyles have different latent class characteristics. By identifying these latent patterns of lifestyle, it is possible to make targeted comprehensive lifestyle improvement recommendations for different classes of participants. However, studies on the association between lifestyle and specific diseases, like cognitive impairment and debilitating conditions, have been undertaken [ 13 ]. No research has examined the connection between various lifestyle choices and the risk of periodontitis to this point.

To fill this gap, the primary aims of this study are: (1) to identify latent lifestyle classes of adults aged 18 years or more using a nationally representative population, and (2) to look at the association between latent lifestyle classes and periodontitis. The results of this study may provide evidence to support future interventional studies aimed at investigating whether targeting specific clusters of unhealthy behaviors could help reduce the prevalence of periodontitis.

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) criteria were used in this study to conduct cross-sectional research. (Additional file 1).

Data source

Data for waves 2009–2010 and 2011–2012 of the National Health and Nutrition Examination Survey (NHANES) were gathered. Detailed information on NHANES has been presented in previous studies [ 14 , 15 , 16 ]. The study’s subjects had at least five full records of their lifestyles and were older than 18 years old. These records were used for latent class analysis. Subjects got a thorough dental health-periodontic examination as part of the NHANES, and all measurements were taken by the periodontal categorization methodology to investigate the association between lifestyle choices and periodontitis. The study had 9034 participants in all.

Lifestyle and lifestyle scores

Lifestyle is comprised of two components [ 17 ]: health behaviors and health beliefs. Health behaviors were assessed through five indicators: smoking, drinking, physical activity (PA), sleep duration, and oral examination. Health beliefs were assessed through one indicator: self-rated oral health. All variables were binary. Smoking was defined as current smoking or quitting for less than one year. Drinking was defined as greater than 12 drinks a year. Through a questionnaire based on the Physical Activity questionnaire, physical activity (PA) data was gathered. Participants disclosed how often and for how long they engaged in vigorous or moderate recreational activities, as well as vigorous or moderate job activities. According to previous NHANES recommendations, the following activities received MET scores: vigorous work-related activity, moderate work-related activity, walking or bicycling, vigorous leisure-time activity, and moderate leisure-time activity, which were given 8, 4, 4, 8, and 4 points, respectively [ 18 ]. The sum of weekly activity minutes was multiplied by the MET score for each activity to determine the total PA. The US PA guidelines stated that low-level PA was classified as 500 MET-min/week and high-level PA as 500 MET-min/week [ 19 ]. Insufficient sleep was defined as a sleep duration of fewer than 7 h per day. Oral examination asked participants if they attended oral health regularly. Participants were considered to have had an oral examination if they indicated engagement in procedures such as check-ups, examinations, or cleanings. Self-rated oral health was self-reported by participants as good or poor. We also calculated a lifestyle score, with one point for having poor health behavior and a score range of 0–6.

Periodontitis

Six locations per tooth are measured as part of the NHANES periodontal examination technique on 28 teeth. Based on clinical attachment loss (AL)and probing depth (PD), periodontitis is diagnosed. The term “periodontitis” was defined in this study using the CDC/AAP classification/case definition [ 20 ]. Patients with mild periodontitis have two proximal sites on distinct teeth that have PD less than 5 mm or two proximal sites with clinical AL less than 4 mm. Patients with moderate periodontitis have one or more of the following: two proximal sites with PD greater than 5 mm, one PD greater than 4 mm, or two proximal sites with clinical AL smaller than 3 mm in distinct teeth. A tooth with a PD of 5 mm or at least two teeth with an AL of greater than or equal to 6 mm indicates severe periodontitis. Participants without any of these symptoms were considered to be free of periodontitis.

Potential confounders related to the association between lifestyle and periodontitis were included in multivariate models, thus covariates were also identified with investigators and categorized in a manner consistent with previous studies [ 21 ]. Covariates including age (< 55 years, ≥ 55 years), sex (male, female), years of education (< 12 years, 12 years, > 12 years) [ 22 ], marriage (no, yes), race (Mexican-American; white, non-Hispanic; black, non-Hispanic; and other), poverty level, BMI and diabetes. Poverty levels were classified into 3 categories according to the algorithm of previous studies: <1.35 classified as low, 1.35-2 classified as medium, and ≥ 2 classified as high [ 23 ]. Three categories of BMI were established: low (18.5 kg/m 2 ), normal (18.5–25 kg/m 2 ), and high (25 kg/m 2 ) [ 24 ]. Participants were classified as having diabetes if they met any of the following criteria: (1) physician-diagnosed diabetes, (2) glycohemoglobin HbA1c(%) ≥ 6.5, (3) fasting glucose (mmol/l) ≥ 7.0, (4) random blood glucose (mmol/l) ≥ 11.1, or (5) two-hour OGTT blood glucose (mmol/l) ≥ 11.1 [ 25 ].

Statistical analysis

For categorical variables, N (%) descriptors were employed. The chi-square test was utilized to assess disparities in baseline data among patients exhibiting distinct degrees of periodontitis. First, we used latent class analysis (LCA) to identify a number of lifestyle classes. LCA is a statistical method that classifies individuals into different groups based on the participants’ response patterns on lifestyle [ 10 ]. According to the likelihood of unique conditions of lifestyle variables in each latent class, lifestyle latent classes are labeled. LCA estimates the parameters using the expectation-maximization algorithm, which accepts the existence of missing values in the data. LCA were conducted, varying the number of classes from 2 to 10. The optimal number of latent classes was determined through a rigorous evaluation based on statistical metrics and interpretability. The optimal LCA was chosen using low values of Akaike’s information criterion (AIC), adjusted Bayesian information criterion (aBIC), Bayesian information criteria (BIC), and consistent Akaike’s information criterion (cAIC) [ 26 ]. The model’s simplicity and interpretability were taken into account in addition to the model fit indicators. Second, we looked at the basic characteristics of various lifestyle groups using weighted logistic regression models. In order to evaluate the association between lifestyle groups and the severity of periodontitis, weighted ordinal logistic regression models were employed. The two-year sample weights for each NHANES period were aggregated into 2009–2012 weights. This research also examined the correlation between lifestyle scores and the severity of periodontitis to compare with earlier findings. All statistical calculations were done in R. The ‘poLCA’ package was used to conduct the study on LCA. The threshold for statistical significance was P < 0.05.

Sample characteristics

Of the 9034 participants included, a total of 4686 (52.40%) were female, with a mean age of 54.08 years, and 62.28% were currently married. Of the total participants, 2057 participants had no periodontitis, 154 had mild periodontitis, 306 had moderate periodontitis, and 6517 had severe periodontitis (Table 1 ). Univariate results showed that different degrees of periodontitis were associated with physical activity, sleep duration, oral examinations, and self-rated oral health. The median score for poor lifestyle was 2.

Identification of the latent class of lifestyle

In the fit results of 2–10 models, all model assessment indicators reached a minimum at 3 classes (Fig. 1 ). Considering interpretability of the results, 3 classes were selected as the optimal number of latent classes of lifestyles. Latent classes of lifestyles were tagged based on the conditional probability of model fitting (Fig. 2 ). The ‘Class 1’ exhibited a prevalence of oral examination (75%), favorable self-rated oral health (92%), and engagement in physical activity (60%). The ‘Class 2’ displayed the lowest frequencies of alcohol consumption (64%) and smoking (73%), yet registered the highest incidence of physical inactivity (98%). The ‘Class 3’ demonstrated a propensity for smoking (72%), alcohol consumption (78%), shorter sleep duration (50%), lack of oral examinations (75%), and suboptimal self-rated oral health (68%).

Statistical metrics for model selection

The distribution of latent classes and conditional probability for 6 lifestyles

Characteristics of the latent class of lifestyle

Figure 3 lists the sociodemographic details of the several latent classes of lifestyle. Participants in the “Class 2” group were more likely to be older, female, and less educated than those in the “Class 1” group, as well as to have lower levels of poverty. The “Class 3” class had a higher likelihood of being younger, having fewer years of education, being unmarried, and having a lower poverty level.

Forest plot for sociodemographic characteristics of latent lifestyle classes based on weighted logistic regression model. ( A ) Sociodemographic characteristics of ‘Class 2’ (Ref = ‘Class 1’). ( B ) Sociodemographic characteristics of ‘Class 3’ (Ref = ‘Class 1’)

Association of lifestyle latent class and scores with periodontitis

Figure 4 illustrates how periodontitis and lifestyle are related. Model 1 assessed the association between periodontitis and poor lifestyle scores. The findings show that participants were more likely to develop periodontitis for each unhealthy lifestyle they increased (OR = 1.24, 95% CI: 1.18–1.31), after controlling for sex, age, marital status, education, race, poverty level, BMI, and diabetes. In model 2, the association between lifestyle latent classes and periodontitis was assessed. The results imply that the risk of periodontitis increased by 80% (95% CI: 1.52–2.13) in the ‘Class 3’ compared to the ‘Class 1’.

Forest plot for the association between lifestyle and periodontitis based on weighted ordinal logistic regression model. ( A ) The association between lifestyle scores and periodontitis. ( B ) The association between lifestyle classes and periodontitis

In this study, we identified 3 lifestyle latent classes based on 6 lifestyle indicators in NHANES: ‘Class 1’ (52%), ‘Class 2’ (13%), and ‘Class 3’ (35%). By conducting the LCA, participants who maintain lifestyles variously could be distinguished and classified between healthy and poor in aggregation. In addition, current evidence ameliorates the knowledge of association between lifestyle and periodontitis by indicating that aggregated poor lifestyle were strongly associated with the severity of periodontitis. These results may improve the understanding of lifestyle clusters and provide an important reference for the development of interventions for periodontitis.

Our study showed that poor lifestyle clusters were associated with age, years of education, and poverty level. Our findings are consistent with previous studies, and the results suggest that different lifestyle classes may be more associated with social environments that may arouse attitudes and practices toward health behaviors, especially physical activity, etc [ 27 , 28 ]. For instance, within our study, individuals who were non-smokers and abstained from alcohol consumption while also lacking physical activity were found to be more prevalent in ‘Class 2’. Furthermore, compared to individuals in ‘Class 1’, those in ‘Class 2’ were more likely to be women. Therefore, lifestyle education and intervention programs for periodontitis control need to take these underlying characteristic differences into account.

Although it is clear that people who have more school years are more likely to lead healthier lifestyles, these connections are not always causal. A study in the Philippines with 1064 participants found that health literacy rather than education level encourages a better lifestyle [ 29 ]. In addition, a UK study that included 9003 participants showed that health literacy did not increase with years of education after educational reform [ 30 ]. Hence, to raise the population’s health literacy and thereby lower the risk of periodontitis, proper intervention programs based on years of education are required when undertaking lifestyle interventions.

Our study also discovered a significant link between unhealthy lifestyle ratings and periodontitis, which is in line with findings from earlier studies [ 6 ]. Nevertheless, a lot of useful information was lost in earlier research; our study altered this. The compromise of valid information stems from the amalgamation of distinct unhealthy lifestyles (such as smoking and drinking) into a singular unhealthy count. In other words, participants reporting the same lifestyle as ‘1’ may encompass both smoking and drinking, each potentially eliciting distinct health effects. This blending of diverse health behaviors undermines the discernment of differential benefits across various health lifestyles. In this study, we could clarify that different lifestyle classes were significantly associated with periodontitis.

In our analysis, the “Class 3”, which included several bad lifestyle choices, significantly increased the development of periodontitis. These individuals were more likely to smoke, drink alcohol, have shorter sleep duration, have oral examinations, and report poor self-rated health. Smoking and alcohol consumption are known risk factors. And the association between sleep duration and periodontitis is gradually being explored. Some findings suggest that either too long or too short a sleep duration increases the risk of adverse health outcomes, such as death, cardiovascular disease, diabetes, and obesity [ 31 , 32 ]. And these adverse health outcomes may further exacerbate the risk of periodontitis [ 33 ]. In addition, participants in the ‘Class 3’ rated themselves as having poor oral health but were reluctant to go for oral examinations, suggesting that this class is weak in health awareness and needs more attention. Thus, a combination of lifestyle aggregation and underlying characteristics is needed to develop appropriate public health policies to reduce the risk of periodontitis.

The practice of lifestyle medicine, such as quitting smoking and drinking, is an important therapy method for periodontitis, which dental health explores and reveals. These discoveries have significant consequences for public health. Furthermore, our discoveries can be effectively incorporated into the S3 level guideline for the treatment of periodontitis. By the guideline’s recommendations, oral hygiene practices are applied consistently throughout the phases of periodontal treatment. A favorable lifestyle is particularly crucial during steps 1 (oral hygiene instruction) and 4 (supportive periodontal care) of periodontitis treatment [ 34 , 35 ]. Our findings facilitate a more precise identification of demographic characteristics within the population, enabling targeted lifestyle promotions to enhance oral hygiene. For instance, placing emphasis on physical activity rather than endorsing smoking and alcohol restrictions for participants among ‘Class 2.’

Despite the good evidence on lifestyle studies for periodontitis interventions, dental practitioners generally lack expertise in lifestyle interventions that have not been well addressed in past dental education [ 36 ]. Our findings and the current situation described above suggest the need to prioritize the development of healthy lifestyle programs in the dental office as a ‘first-line treatment’ for periodontitis [ 37 ].

This study is one of the first, as far as we are aware, to examine the association between latent lifestyle patterns and periodontitis. However, there are some limitations to this study. First off, since this research was cross-sectional, it’s difficult to determine whether a certain way of living causes periodontitis. Second, we were unable to determine the effect of lifestyle modifications on periodontitis. Because the data on smoking, alcohol intake, and exercise were an evaluation of recent status, it was not possible to determine the relevance of alcohol and smoking cessation on periodontitis. Third, it is crucial to recognize the potential overlap between measures of oral examination and self-assessment of oral health, potentially influencing statistical outcomes. However, these effects are manageable for several reasons. (1) Oral examination and self-rated oral health represent distinct dimensions of measurement; the former is an objective health behavior, and the latter is a subjective health evaluation. (2) LCA can address the impact of overlapping variables resulting from the classification of individuals, provided that local independence is satisfied during these lifestyle measurements. LCA, to a certain extent, assists in mitigating the impact of overlapping variables. Fourth, even if the survey was done face-to-face by trained professionals, the impact of measurement error cannot be entirely disregarded. Furthermore, the use of binary numbers to represent lifestyle might impose considerable restrictions because severe activity and moderate exercise may have similar MET scores but different consequences. In order to categorize lifestyles and determine whether there is a link between them and periodontitis, future studies must use more objective lifestyle metrics.

In conclusion, we discovered two classes of bad lifestyle patterns—“Class 2” and “Class 3”—that are linked to an increased risk of periodontitis. These associations may offer pertinent cues for devising lifestyle promotion plans and could potentially contribute to formulating etiological hypotheses in accordance with the S3 level guideline for the treatment of periodontitis.

Data availability

This study used public data at https://www.cdc.gov/nchs/nhanes/index.htm .

Slots J. Periodontitis: facts, fallacies and the future. Periodontol 2000 2017, 75(1):7–23.

Eke PI, Borgnakke WS, Genco RJ. Recent epidemiologic trends in periodontitis in the USA. Periodontol 2000. 2020;82(1):257–67.

Article PubMed Google Scholar

Irwandi RA, Chiesa ST, Hajishengallis G, Papayannopoulos V, Deanfield JE, D’Aiuto F. The roles of neutrophils linking Periodontitis and Atherosclerotic Cardiovascular diseases. Front Immunol. 2022;13:915081.

Article CAS PubMed PubMed Central Google Scholar

Teles F, Collman RG, Mominkhan D, Wang Y. Viruses, periodontitis, and comorbidities. Periodontol 2000. 2022;89(1):190–206.

Roguljic M, Vuckovic M, Gelemanovic A, Kovacevic K, Oreskovic J, Radic M, Bozic D, Radic J. Risk factors of severe periodontitis in kidney transplant recipients: a case-control study. J Periodontol 2023.

Iwasaki M, Borgnakke WS, Ogawa H, Yamaga T, Sato M, Minagawa K, Ansai T, Yoshihara A, Miyazaki H. Effect of lifestyle on 6-year periodontitis incidence or progression and tooth loss in older adults. J Clin Periodontol. 2018;45(8):896–908.

Bartold PM. Lifestyle and periodontitis: the emergence of personalized periodontics. Periodontol 2000. 2018;78(1):7–11.

Chapple IL, Bouchard P, Cagetti MG, Campus G, Carra MC, Cocco F, Nibali L, Hujoel P, Laine ML, Lingstrom P, et al. Interaction of lifestyle, behaviour or systemic diseases with dental caries and periodontal diseases: consensus report of group 2 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. J Clin Periodontol. 2017;44(Suppl 18):S39–51.

PubMed Google Scholar

Loef M, Walach H. The combined effects of healthy lifestyle behaviors on all cause mortality: a systematic review and meta-analysis. Prev Med. 2012;55(3):163–70.

Sinha P, Calfee CS, Delucchi KL. Practitioner’s guide to latent class analysis: methodological considerations and common pitfalls. Crit Care Med. 2021;49(1):e63–79.

Article PubMed PubMed Central Google Scholar

Ghanbari J, Mohammadpoorasl A, Jahangiry L, Farhangi MA, Amirzadeh J, Ponnet K. Subgroups of lifestyle patterns among hypertension patients: a latent-class analysis. BMC Med Res Methodol. 2018;18(1):127.

Nudelman G, Yakubovich S. Patterns of health lifestyle behaviours: findings from a representative sample of Israel. BMC Public Health. 2022;22(1):2099.

Zhang YB, Chen C, Pan XF, Guo J, Li Y, Franco OH, Liu G, Pan A. Associations of healthy lifestyle and socioeconomic status with mortality and incident cardiovascular disease: two prospective cohort studies. BMJ. 2021;373:n604.

Ahluwalia N, Dwyer J, Terry A, Moshfegh A, Johnson C. Update on NHANES Dietary Data: Focus on Collection, Release, Analytical considerations, and uses to inform Public Policy. Adv Nutr. 2016;7(1):121–34.

Paulose-Ram R, Graber JE, Woodwell D, Ahluwalia N. The National Health and Nutrition Examination Survey (NHANES), 2021–2022: Adapting Data Collection in a COVID-19 environment. Am J Public Health. 2021;111(12):2149–56.

Li X, Wang L, Yang L, Liu X, Liu H, Mu Y. The association between plain water intake and periodontitis in the population aged over 45: a cross-sectional study based on NHANES 2009–2014. BMC Oral Health. 2024;24(1):27.

Agnew MD, Pettifor H, Wilson C. Lifestyle, an integrative concept: cross-disciplinary insights for low-carbon research. WIRE Energy Environ. 2023;12(6):e490.

Article Google Scholar

Chu NM, Hong J, Harasemiw O, Chen X, Fowler KJ, Dasgupta I, Bohm C, Segev DL, McAdams-DeMarco MA. Global Renal Exercise N: chronic kidney disease, physical activity and cognitive function in older adults-results from the National Health and Nutrition Examination Survey (2011–2014). Nephrol Dial Transpl. 2022;37(11):2180–9.

Article CAS Google Scholar

National Health and Nutrition Examination. Survey 2011–2012 Data Documentation, Codebook, and Frequencies: Physical Acitivty (PAQ_G) [ https://wwwn.cdc.gov/Nchs/Nhanes/2011-2012/PAQ_G.htm] .

Eke PI, Dye BA, Wei L, Slade GD, Thornton-Evans GO, Borgnakke WS, Taylor GW, Page RC, Beck JD, Genco RJ. Update on prevalence of periodontitis in adults in the United States: NHANES 2009 to 2012. J Periodontol. 2015;86(5):611–22.

Rutherford ER, Vandelanotte C, Chapman J, To QG. Associations between depression, domain-specific physical activity, and BMI among US adults: NHANES 2011–2014 cross-sectional data. BMC Public Health. 2022;22(1):1618.

Mainous AG 3rd, Tanner RJ, Jo A, Anton SD. Prevalence of prediabetes and abdominal obesity among healthy-weight adults: 18-Year Trend. Ann Fam Med. 2016;14(4):304–10.

Fang Y, Dong Z, Huang T, Wang L, Fan W, Wang B, Yang Q, Xu M, Li D, Fang Y, et al. The role of socioeconomic status and oxidative balance score in erectile dysfunction: a cross-sectional study. Heliyon. 2023;9(11):e22233.

Stanley A, Schuna J, Yang S, Kennedy S, Heo M, Wong M, Shepherd J, Heymsfield SB. Distinct phenotypic characteristics of normal-weight adults at risk of developing cardiovascular and metabolic diseases. Am J Clin Nutr. 2020;112(4):967–78.

Liu C, He L, Li Y, Yang A, Zhang K, Luo B. Diabetes risk among US adults with different socioeconomic status and behavioral lifestyles: evidence from the National Health and Nutrition Examination Survey. Front Public Health. 2023;11:1197947.

MacLean E, Dendukuri N. Latent class analysis and the need for Clear Reporting of methods. Clin Infect Dis. 2021;73(7):e2285–6.

Hernandez EM, Margolis R, Hummer RA. Educational and gender differences in Health Behavior Changes after a Gateway diagnosis. J Aging Health. 2018;30(3):342–64.

Chuang YC, Chuang KY. Gender differences in relationships between social capital and individual smoking and drinking behavior in Taiwan. Soc Sci Med. 2008;67(8):1321–30.

Hoffmann R, Lutz SU. The health knowledge mechanism: evidence on the link between education and health lifestyle in the Philippines. Eur J Health Econ. 2019;20(1):27–43.

Johnston DW, Lordan G, Shields MA, Suziedelyte A. Education and health knowledge: evidence from UK compulsory schooling reform. Soc Sci Med. 2015;127:92–100.

Shan Z, Ma H, Xie M, Yan P, Guo Y, Bao W, Rong Y, Jackson CL, Hu FB, Liu L. Sleep duration and risk of type 2 diabetes: a meta-analysis of prospective studies. Diabetes Care. 2015;38(3):529–37.

Yin J, Jin X, Shan Z, Li S, Huang H, Li P, Peng X, Peng Z, Yu K, Bao W et al. Relationship of Sleep Duration with all-cause Mortality and Cardiovascular events: a systematic review and dose-response Meta-analysis of prospective cohort studies. J Am Heart Assoc 2017, 6(9).

Han DH, Kim MS, Kim S, Yoo JW, Shen JJ. Sleep time and duration are associated with periodontitis in a representative sample of koreans. J Periodontol. 2022;93(2):208–17.

Article CAS PubMed Google Scholar

Sanz M, Herrera D, Kebschull M, Chapple I, Jepsen S, Beglundh T, Sculean A, Tonetti MS, Participants EFPW, Methodological C. Treatment of stage I-III periodontitis-the EFP S3 level clinical practice guideline. J Clin Periodontol. 2020;47(Suppl 22):4–60.

Herrera D, Sanz M, Kebschull M, Jepsen S, Sculean A, Berglundh T, Papapanou PN, Chapple I, Tonetti MS, Participants EFPW, et al. Treatment of stage IV periodontitis: the EFP S3 level clinical practice guideline. J Clin Periodontol. 2022;49(Suppl):4–71.

Albert D, Ward A. Tobacco cessation in the dental office. Dent Clin North Am. 2012;56(4):747–70.

Fiorini T, Musskopf ML, Oppermann RV, Susin C. Is there a positive effect of smoking cessation on periodontal health? A systematic review. J Periodontol. 2014;85(1):83–91.

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Acknowledgements

The NHANES study, which was conducted by the national center for health statistics, provided the data used in this paper. (NCHS). The nhanes participants and researchers are acknowledged for their contributions to this significant study by the authors.

This study was supported by the Sanming Project of Medicine in Shenzhen (SZSM202111012, Oral and Maxillofacial Surgery Team, Professor Yu Guangyan, Peking University Hospital of Stomatology), Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties (No. SZGSP008), Fund for Shenzhen Clinical Research Center for Oral Diseases (20210617170745001).

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Jianlin Lin, Tao Pei & Hongyu Yang

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Guangdong Provincial High-level Clinical Key Specialty, Shenzhen, Guangdong Province, China

Guangdong Province Engineering Research Center of Oral Disease Diagnosis and Treatment, Shenzhen, Guangdong Province, China

The Institute of Stomatology, Peking University Shenzhen Hospital, Shenzhen Peking University The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China

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JL, PT, and HY conceived and designed the study; JL conducted statistical analyses; PT and HY supervised the data analyses; JL, PT, and HY contributed to manuscript writing. All authors have read and approved the final manuscript.

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Correspondence to Tao Pei or Hongyu Yang .

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The U.S. National Centre for Health Statistics Ethics Review Board approved the NHANES survey protocols (Protocol #2005-06 and Protocol #2011–2017), and the study complied with the Declaration of Helsinki. All participants gave written informed consent.

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Lin, J., Pei, T. & Yang, H. Association between modifiable lifestyle pattern and periodontitis: a cross-sectional study based on NHANES. BMC Oral Health 24 , 591 (2024). https://doi.org/10.1186/s12903-024-04207-8

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DOI : https://doi.org/10.1186/s12903-024-04207-8

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Case Study Questions for Class 8 Science Chapter 12 Friction
Case Study Questions for Class 8 Science Chapter 12 Friction Here we are providing case study questions for CBSE Class 8 Science Chapter 12 Friction. Case Study Questions Question 1: Friction is a force between two surfaces that are sliding, or trying to slide, across each other. Friction always works in the direction opposite to … Continue reading Case Study Questions for Class 8 Science ...
Friction Class 8 Case Study Questions Science Chapter 9
Questions. Question 1: Read the given passage below and answer the question: (I) The force required to overcome friction at the instant an object starts moving from rest is a measure of static friction. On the other hand, the force required to keep the object moving with the same speed is a measure of sliding friction.
Friction CBSE Class 8 Science Notes Chapter 12
Friction is a force that comes into play when two surfaces come in contact with each other. The Frictional force or the force of Friction acts in the opposite direction of the motion of the object. The force of Friction opposes the relative motion between the surfaces of two moving objects. Figure 1 Force of Friction.
NCERT Solutions Class 8 Science Chapter 12 Friction
NCERT Solutions for Class 8 Science Chapter 12 Friction are crucial resources for the students of 8th Standard. The solutions provided here aim to help students understand the chapter in an interesting way. These Chapter 12 Friction Solutions are created by subject experts, according to the latest CBSE guidelines and syllabus (2023-24).
NCERT Solutions for Class 8 Science Chapter 12 Friction
Friction Class 8 Science NCERT Intext Activities Solved. Activity 1 (NCERT Textbook, Page 146) ... The reason for this difference could be that in the first case, since the brick surface in contact with the ground is rough, the surface gets greater force of friction. ... More CBSE Class 8 Study Material. NCERT Solutions for Class 8 Maths;
Friction Class 8 Notes CBSE Science Chapter 12 [PDF]
The disadvantages of frictional force have been discussed clearly in class 8 Science chapter 12 notes. A few of the major drawbacks are - (1) wear and tear of objects moving across a surface, (2) friction causes the production of heat leading to energy wastage, (3) frictional force is responsible for causing a reduction in speed of an object ...
Important Questions for CBSE Class 8 Science Chapter 12
Class 8 Chapter 12 Friction Summary. Friction - It is the external force that opposes the relative motion between the two surfaces in contact. Friction acts on both surfaces which are in contact with each other. When one object moves in relative to the other object is known as relative motion.
NCERT Solutions for Class 8 Science Chapter 12
The concept of Friction is best described in NCERT Solutions Class 8 Science Chapter 12 by Vedantu. Class 8 Science Chapter 12 NCERT Solutions is a great platform that provides the fundamentals of the chapter and accurate answers to complex numerical questions. NCERT Solutions Science Chapter 12 is what students require to ace their exams.
NCERT Solutions for Class 8 Science Chapter 12 Friction
Detailed Explanations: The friction class 8 NCERT Solutions offer detailed and easy-to-understand explanations for all the questions and concepts presented in the chapter. This helps students grasp the material effectively. Real-Life Examples: The class 8 science chapter 12 NCERT solutions include real-life examples and scenarios to illustrate ...
Friction Class 8 Important Questions and Answers
The factors on which fluid friction depends are as following: (i) The fluid friction of an object depends on its speed with respect to fluid. (ii) The fluid friction of an object also depends on the shape of the object. (iii) The frictional force due to fluids also depends on the nature of the fluid. Important questions of Class 8 Science ...
Friction Class 8 Extra Questions Science Chapter 12
Question 6. Whenever the surfaces in contact tend to move or move with respect to each other, the force of friction comes into play. (a) only if the objects are solid. (b) only if one of the two objects is liquid. (c) only if one of the two objects is gaseous. (d) irrespective of whether the objects are solid, liquid or gaseous.
Friction Class 8 Science Extra Questions and Answers
Question 23: Name the device which is attached to heavy luggage (such as a heavy suitcase) to move it easily by pulling. Answer: Rollers. Question 24: Give one example from everyday life where wheels (or rollers) are used to reduce friction. Answer: Suitcase.
Friction Class 8 Notes Science Chapter 12
Friction is the force opposite to the direction of motion. Friction is the force that acts when one object tries to move or slide over the surface of another object. It can be defined as the resistance of motion when one objects rub against other. Friction works against the motion and acts in the opposite direction.
NCERT Solutions for Class 8 Science Chapter 12 Friction
Class 8 Science Chapter 12 Friction Exercise Questions and Answers. Question 1. Fill in the blanks. (a) Friction opposes the _______ between the surfaces in contact with each other. Answer: Relative motion. (b) Friction depends on the _______ of surfaces. Answer:
NCERT Revision Notes Chapter 12 Friction Class 8 Science
6. Fluid Friction. Answer. → Fluid friction is minimised by giving suitable shapes to vehicles moving through fluids. • Fluid friction is also called drag. → Friction force depends upon the speed of the object with respect to the fluid. → Friction force depends upon the shape of the and nature of the fluid. Exercise.
Notes of Ch 12 Friction| Class 8th Science
Notes of Ch 12 Friction| Class 8th Science. → The vehicles, any object, moving over the surface of another object slows down due to the force of friction applied on it. → It is an opposing force that acts between surfaces in contact moving with respect to each other. → It always opposes relative motion between two surfaces.
Friction Extra Questions for Class 8
This Friction Extra Questions for Class 8 is prepared keeping in mind the latest syllabus of CBSE . This has been designed in a way to improve the academic performance of the students. If you find mistakes , please do provide the feedback on the mail. Also Read. Notes. Friction Class 8 Notes; Assignments. NCERT Solution for Class 8 Science Friction
Lakhmir Singh Solutions for Class 8 Science Chapter 12 Friction
Lakhmir Singh Science Class 8 Solutions for Chapter 12 Friction. Friction is defined as the force which opposes the motion of an object on the surface it is in contact with. It has pros and cons. Friction makes it easy to walk on the roads without slipping, which is an advantage for us. On the other hand, moving heavy objects becomes difficult ...
Friction Class 8 Chapter 12 Notes
Friction Class 8 Notes - Chapter 12. According to the CBSE Syllabus 2023-24, this chapter has been renumbered as Chapter 9. The Class 8 Science chapter 12 Friction discusses friction and various factor affecting it. The force which opposes the relative motion between two surfaces in contact is known as friction. It acts on both surfaces.
NCERT Solutions for Class 8 Science Chapter 12 Friction
By getting access to NCERT Solutions for Class 8 Science Chapter 12- Friction, students can easily understand all the chapter's concepts. NCERT Solutions Class 8 Science Chapter-wise List. Chapter 1 - Crop Production and Management. Chapter 2 - Microorganisms : Friend and Foe. Chapter 3 - Synthetic Fibres and Plastics.
NCERT Exemplar Class 8 Science Solutions Chapter 12
NCERT Exemplar Solutions Class 8 Science Chapter 12 - Free PDF Download. The NCERT Exemplar for Class 8 Science Chapter 12 Friction covers the fundamentals of the important Physics-related topics included in the CBSE Class 8 Syllabus 2023-24. This exemplar solution helps you in gaining higher-level knowledge by providing further information for your preparation.
Class 8 Science Case Study Question
CBSE Class 8 Science Case Study Question. Chapter 1 Crop Production and Management Case Study Question. Chapter 2 Microorganisms: Friend and Foe Case Study Question. Chapter 3 Synthetic Fibres and Plastics Case Study Question. Chapter 4 Materials: Metals and Non-Metals Case Study Question.
Friction Class 8 Extra Questions and Answers Science Chapter 12
In this case, you must plow through to move, thus creating resistive force. (iv) Weight of the body: The greater is the weight of the body, the greater will be the force of friction. If we push a heavy box, it will require greater force to move as the force of friction is greater. ... Friction Class 8 Extra Questions Value Based (VBQs) Question 1.
Association between modifiable lifestyle pattern and periodontitis: a
Periodontitis can be avoided with a healthy lifestyle. However, studies have only looked at one lifestyle, ignoring the connection between lifestyle patterns and periodontitis. The purpose of this study was to look at the association between modifiable lifestyle patterns and periodontitis. Data were obtained from the National Health and Nutrition Examination Survey in 2009-2010 and 2011-2012.
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[Federal Register Volume 89, Number 98 (Monday, May 20, 2024)] [Rules and Regulations] [Pages 44144-44461] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2024-08568] Vol. 89 Monday, No. 98 May 20, 2024 Part IV Department of Labor ----- Occupational Safety and Health Administration ----- 29 CFR Part 1910 Hazard Communication Standard; Final Rule ...

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