 # NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure

## NCERT Solutions for Class 8 Science Chapter 11 – Free PDF Download

*According to the CBSE Syllabus 2023-24, this chapter has been renumbered as Chapter 7.

NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure are provided here to help students to follow the concepts in an easy way. The topic of Force and Pressure is one of the key concepts in Science. It is very important to grasp every bit of this Chapter as they are basics for all students’ future endeavours. help them to attain perfection on the chapter by providing answers to a variety of questions such as MCQs, fill in the blanks, match the following, true or false and descriptive answer types questions.

In order to score good marks in the Class 8 Science examination and to grasp the concepts involved in the chapter, students are advised to refer to the NCERT Solutions for Class 8 Science thoroughly. Answers provided here will help students to get the knowledge on the concept of Force, magnitude and direction of force, change in its state of motion or a change in its shape, definition of pressure, and the exertion of pressure on liquid and gases. Access the Chapter’s NCERT Solutions for Class 8 of Science from the link provided below.

## NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure

### Access answers of NCERT Class 8 Science Chapter 11 Force and Pressure

Exercise Questions

1. Give two examples each of situations in which you push or pull to change the state of motion of objects.

Soln:

Examples of situations in which you push or pull to change the state of motion of objects are

1. Pull situations

a) In order to open a drawer, we have to pull it. This action changes the state of motion of the drawer.

b) To draw water from the well, the rope is pulled. This action changes the state of motion of the bucket.

2. Push Situations

a) A football is pushed by the foot of a player. This action changes the state of motion of the ball.

b) In order to change the place of the heavy box from one room to another, we have to push it. This action changes the motion of the box.

2. Give two examples of situations in which applied force causes a change in the shape of an object.

Soln:

The forces which change the shape of an object are as follows:

i) By pressing the clay between the hands, it deforms.

ii) The shape of the plastic bottle changes by squeezing it.

3. Fill in the blanks in the following statements.

(a) To draw water from a well, we have to __________ at the rope.

(b) A charged body __________ an uncharged body towards it.

(c) To move a loaded trolley, we have to __________ it.

(d) The north pole of a magnet __________the north pole of another magnet.

Soln:

1. To draw water from a well, we have to pull at the rope.
2. A charged body attracts an uncharged body towards it.
3. To move a loaded trolley, we have to pull or push it.
4. The north pole of a magnet repels the north pole of another magnet.

4. An archer stretches her bow while taking aim at the target. She then releases the arrow, which begins to move towards the target. Based on this information, fill up the gaps in the following statements using the following terms.

muscular, contact, non-contact, gravity, friction, shape, attraction

(a) To stretch the bow, the archer applies a force that causes a change in its __________.

(b) The force applied by the archer to stretch the bow is an example of __________ force.

(c) The type of force responsible for a change in the state of motion of the arrow is an example of a __________ force.

(d) While the arrow moves towards its target, the forces acting on it are due to __________ and that due to __________ of air

Soln:

(a) To stretch the bow, the archer applies a force that causes a change in its shape.

(b) The force applied by the archer to stretch the bow is an example of muscular force.

(c) The type of force responsible for a change in the state of motion of the arrow is an example of a contact force.

(d) While the arrow moves towards its target, the forces acting on it are due to gravity and that due to friction of air.

5. In the following situations, identify the agent exerting the force and the object on which it acts. State the effect of the force in each case.

(a) Squeezing a piece of lemon between the fingers to extract its juice.

(b) Taking out paste from a toothpaste tube.

(c) A load suspended from a spring while its other end is on a hook fixed to a wall.

(d) An athlete making a high jump to clear the bar at a certain height

Soln:

a) We make a muscular force to extract the juice of the lemon by squeezing it. As a result, the shape of the lemon gets changed.

b) To take out paste from the toothpaste tube, we use our muscular force. This muscular force acting on the toothpaste tube leads to a change in its shape.

c) Here, the suspended load exerts a force on the spring and pushes the spring downwards. As a result, the spring gets stretched. Hence, its shape gets changed.

d) The feet of the athlete exert muscular force on the ground, which pushes the ground. This allows them to jump over the bar. As a result, their state of motion gets changed.

6. A blacksmith hammers a hot piece of iron while making a tool. How does the force due to hammering affect the piece of iron?

Soln:

A blacksmith uses their muscular force while hammering a hot piece of iron. The muscular force changes the shape of the iron so that it can be given the desired shape.

7. An inflated balloon was pressed against a wall after it had been rubbed with a piece of synthetic cloth. It was found that the balloon stuck to the wall. What force might be responsible for the attraction between the balloon and the wall?

Soln:

When an inflated balloon is rubbed with a piece of synthetic cloth, it becomes charged. A charged body attracts an uncharged body. When this charged balloon is pressed against a wall, it sticks to the wall. Thus, the electrostatic force acts between the charged balloon and the wall.

8. Name the forces acting on a plastic bucket containing water held above ground level in your hand. Discuss why the forces acting on the bucket do not bring a change in its state of motion.

Soln:

For holding the bucket of water above the ground, we use muscular force. This muscular force acts against the force of gravity that pulls the bucket towards the ground. The two forces are equal in magnitude but opposite in direction. Therefore, the net force on the bucket is zero. Hence, there is no change in the state of motion.

9. A rocket has been fired upwards to launch a satellite in its orbit. Name the two forces acting on the rocket immediately after leaving the launching pad.

Soln:

The force of gravity is the one which acts on the rocket to pull it towards the ground, and the other one is the force of friction due to the earth’s atmosphere, which opposes its motion.

10. When we press the bulb of a dropper with its nozzle kept in water, the air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water gets filled in the dropper. The rise of water in the dropper is due to

(a) pressure of water

(b) gravity of the earth

(c) shape of rubber bulb

(d) atmospheric pressure

Soln:

a) Due to the atmospheric pressure, there is a rise of water in the dropper.

When all the air escapes from the nozzle, the atmospheric pressure, which is acting on the water, forces the water to fill up the nozzle of the dropper.

### Class 8 Science NCERT Solutions for Chapter 11 Force and Pressure

The NCERT Solutions for Class 8 will give students clarity regarding various aspects of this chapter in Science, which will consequently help them to solve questions from this chapter easily. Along with answers to the textbook questions, these solutions have exemplary problems, worksheets, important questions and HOTS.

In this Chapter 11, Force and Pressure, students will come across questions on applied force and changes in the object shape. Some questions, like the difference between force and pressure, appear prominently in the exams, which are explained in detail in these NCERT Solutions.

The other types of questions that are crucial are based on objects and force. Practising these types of questions in this chapter will ensure they have a good grasp of the subject. Here, the NCERT Solutions for Class 8 Science Chapter 11 PDF is also available, and students can access them offline by downloading it for free as well.

### Subtopics of NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure

1. Force – A Push or a Pull
2. Forces are Due to an Interaction
3. Exploring Forces
4. A Force Can Change the State of Motion
5. Force Can Change the Shape of an Object
6. Contact Forces
7. Non-Contact Forces
8. Pressure
9. Pressure Exerted by Liquids and Gases
10. Atmospheric Pressure

Students must study these NCERT Solutions meticulously to excel in the subject. These NCERT Solutions are prepared according to the latest syllabus of CBSE. Also, check the other NCERT Solutions of different classes and subjects at BYJU’S for free.

## Frequently Asked Questions on NCERT Solutions for Class 8 Science Chapter 11

Q1

### What are the sub-topics covered under Chapter 11 of NCERT Solutions for Class 8 Science?

The subtopics covered under Chapter 11 of NCERT Solutions for Class 8 Science are
Force – A Push or a Pull
Forces are Due to an Interaction
Exploring Forces
A Force Can Change the State of Motion
Force Can Change the Shape of an Object
Contact Forces
Non-Contact Forces
Pressure
Pressure Exerted by Liquids and Gases
Atmospheric Pressure
Q2

### Can students rely on the NCERT Solutions for Class 8 Science Chapter 11 from BYJU’S?

The NCERT Solutions for Class 8 Science Chapter 11 from BYJU’S are designed with the main aim of helping students to focus on important concepts. Each and every minute detail is explained with utmost care to improve the conceptual knowledge among students. The solutions also contain various shortcut techniques which can be used to remember the concepts effectively. Students can refer to the solutions while answering the textbook questions and understand the method of answering them without any difficulty.
Q3

### Name the forces acting on a plastic bucket containing water held above ground level in your hand, which is studied in Chapter 11 of NCERT Solutions for Class 8 Science.

The kinetic energy or mechanical energy of an object is the energy possessed by a body by virtue of its motion. For holding the bucket of water above the ground, we use muscular force. This muscular force acts against the force of gravity that pulls the bucket towards the ground. The two forces are equal in magnitude but opposite in direction. Therefore, the net force on the bucket is zero. Hence, there is no change in the state of motion. This concept can be clearly understood by the students using the NCERT Solutions created by the faculty at BYJU’S.