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

NCERT solutions for class 8 science chapter 11 Force and Pressure: You must have seen the stickers of push and pull on doors at different places. By pushing or pulling we make the door to move either in a backward or in a forward direction. So push and pull is nothing but a force and this force changes the state of motion of an object in a particular direction. The solutions of NCERT for class 8 science chapter 11 force and pressure help you to understand the concept and score good marks in the exam. In the chapter force and pressure, you will study the different types of forces and the concept of pressure. There are 10 questions explained in the CBSE NCERT solutions for class 8 science chapter 11 force and pressure. All 10 questions are based on real-life examples. While learning the chapter observe the types of the force around you. The NCERT solutions for class 8 science chapter 11 force and pressure are helpful to evaluate how well you have grasped the concept of the chapter. While solving any questions of NCERT, first give a try your self and then go for the solutions of NCERT questions.

## The main topics of NCERT Class 8 Science Chapter 11 are listed below:

11.1. Force – A Push or Pull

11.2. Forces are due to an Interaction

11.3.  Exploring Forces

11.4. A Force can Change the State of Motion

11.5. Force can Change the Shape of an Object

11.6.  Contact Forces

11.7.  Non-contact Forces

11.8.  Pressure

11.9. Pressure Exerted by Liquids and Gases

11.10.  Atmospheric Pressure

## NCERT solutions for class 8 science chapter 11 force and pressure exercise:

Two examples of the situation in which the state of motion of an object is changed through a push are as follows:

(a) A table whose position in a room has to be changed is moved by pushing it.

(b) In a match of cricket, the batsman hits the ball by pushing it with a bat.

Two examples of the situation in which the state of motion of an object is changed through a pull are as follows:

(a) In a game of tug of war, both teams try to bring the rope towards their side by pulling it.

(b) A train moves when the engine pulls the rest of the bogies.

Two examples of situations in which applied force causes a change in the shape of an object are as follows:

(a) The shape of a rubber band changes (it stretches) once it is pulled from both ends.

(b) The shape of dough is changed before making it into a roti.

Q3. 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.

(a) To draw water from a well we have to pull at the rope.
(b) A charged body attracts an uncharged body towards it.
(c) To move a loaded trolley we have to either pull or push it.
(d) The north pole of a magnet repels the north pole of another magnet.

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.

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 the friction of air.

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

The fingers exert muscular force on the lemon. As an effect of this force, the lemon gets squeezed.

(b) Taking out paste from a toothpaste tube.

We use our fingers to apply muscular force on the toothpaste tube. This applied muscular force changes the shape of the tube causing the toothpaste to come out of it.

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

The load pulls the spring. As an effect of this pull, the spring stretches.

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

The athlete pushes the ground using muscular force. This causes the athlete to rise in the air.

While hammering a hot piece the blacksmith applies force on it using the hammer thus causing a change in the shape of the piece of iron. For example, the blacksmith can make a cylindrical block of iron to rectangular block by heating it and hammering.

On rubbing the balloon against a piece of synthetic cloth the balloon gains charge. The wall is uncharged and is attracted by the charged balloon since a charged body attracts an uncharged body. The electrostatic force is responsible for the attraction between the balloon and the wall.

The forces acting on the bucket are muscular force applied by our hand and gravitational force. The forces acting do not bring a change in the state of the motion as the forces are equal in magnitude and act in the opposite direction.

Two forces acting on the rocket are the gravitational force and friction of the air in the atmosphere. The gravitational force pulls the rocket towards the earth and the friction force also opposes the motion of the rocket.

## Q13. When we press the bulb of a dropper with its nozzle kept in water, 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.

The rise of water in the dropper is due to atmospheric pressure. The atmospheric pressure is more than the pressure inside the dropper thus pushing the water inside it.

## NCERT Solutions For Class 8 Science Chapter wise:

 NCERT solutions for class 8 science chapter 1 Crop Production And Management Solutions of NCERT class 8 science chapter 2 Microorganisms: Friend And Foe CBSE NCERT solutions for class 8 science chapter 3 Synthetic Fibres And Plastics NCERT solutions for class 8 science chapter 4 Materials: Metals And Non-Metals CBSE NCERT solutions for class 8 science chapter 5 Coal and Petroleum NCERT solutions for class 8 chapter 6 Combustion and Flame Solutions of NCERT class 8 science chapter 7 Conservation of Plants and Animals CBSE NCERT solutions for class 8 science chapter 8 Cell Structure and Functions NCERT solutions for class 8 science chapter 9 Reproduction in Animals Solutions of NCERT class 8 science chapter 10 Reaching the Age of Adolescence NCERT solutions for class 8 science chapter 11 Force and Pressure CBSE NCERT solutions for class 8 science chapter 12 Friction Solutions of NCERT class 8 science chapter 13 Sound NCERT solutions for class 8 chapter 14 science Chemical Effects of Electric Current Solutions of NCERT class 8 science chapter 15 Some Natural Phenomena CBSE NCERT solutions for class 8 science chapter 16 Light Solutions of NCERT class 8 science chapter 17 Stars and The Solar System NCERT solutions for class 8 science chapter 18 Pollution of Air and Water

## NCERT solutions for class 8 science chapter 11 Force and Pressure- Points to remember:

The questions explained in the NCERT solutions for class 8 science chapter 11 force and pressure are based on the following points.

• Force is either a push or a pull on an object resulting from interaction with another object.
• The direction of motion of an object can be changed by applying force.
• Force can alter the shape of an object
• Force can influence the state of motion
• The pressure is the force per unit area.
• The pressure exerted by the air around us is known as atmospheric pressure.
• The value of atmospheric pressure is very large, but our body is not feeling it because the pressure inside the body is also equal to the atmospheric pressure and balances the pressure from outside.

There are so many interesting examples and situations that are given in the NCERT book grade eight-chapter 11. You can do all the activities given in the NCERT book and it will be a fun and a learning experience. CBSE NCERT solutions for class 8 science chapter 11 force and pressure helps students in solving homework problems also.