NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure

You will get NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure that will be useful in passing exams with flying colours. NCERT Solutions for Science prepared by our experts try to provide all round clarity of questions. These NCERT Solutions are helpful resources that can help you not only cover the entire syllabus but also provide in depth analysis of the topics. It help in solving the difficulties that lie ahead with ease.

It is very challenging to score good marks in tests that is why we have prepared Chapter 11 NCERT Questions and Answers for Class 8 Science. Students can cross check their answers and also whether they learned it properly or not. These are helpful in building a great foundation of concepts and make easy for the students to understand basics.

NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure

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Study Material for Class 8 Science Chapter 11 Force and Pressure

Page No: 142

Exercise

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

Two examples of push force are as follows:
→ A heavy box at rest is pushed to move it from one room to another. This changes the state of motion of the box.
→ A player pushes a football using his foot. This changes the state of motion of the ball.

Two examples of pull force are as follows:
→ Rope is pulled to draw water from a well. This changes the state of motion of the water bucket.
→ A drawer is pulled to open it. This changes the state of motion of the drawer.

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

Two examples of forces that cause a change in the shape of an object are as follows:
→ Making of bread from dough
→ Deformation of clay by pressing it between the hands.

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.

(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 push or pull it.
(d) The north pole of a magnet repels the north pole of another magnet.

Page No: 143

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.

(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.

Agent exerting the force – Fingers
Object on which force acts – Lemon
Effect of force – Change in shape of lemon

(b) Taking out paste from a toothpaste tube.

Agent exerting the force – Fingers
Object on which force acts – toothpaste tube
Effect of force – Change in shape of toothpaste tube.

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

Agent exerting the force – Load
Object on which force acts – Spring
Effect of force – Change in shape of spring.

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

Agent exerting the force – Muscles of Athlete
Object on which force acts – Athlete
Effect of force – Change of state of motion of athlete

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?

When a blacksmith hammers a hot piece of iron, he uses his muscular force. This muscular force changes the shape of the iron so that it can be given a desired shape.

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

Electrostatic force is responsible for the attraction between the 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.

In this case, muscular force is acting in upward direction and the force of gravity is acting in downward direction. Both forces are acting in opposite directions to each other and hence nullify the effect of each other. Due to this, there is no change in the state of motion of the bucket.

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.

The two forces acting on the rocket are the force of gravity, which pulls the rocket towards the ground, and the force of friction due to earth's atmosphere, which opposes its motion.

10. 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

(d) atmospheric pressure

Chapter 11 Force and Pressure Class 8 Science NCERT Solutions

NCERT Textbook will provide you with a lot of interesting topics thus these NCERT Solutions will be useful in understanding in depth concepts well. It will improve your awareness skills sharply and you can easily memorize more things precisely. Detailed explanation provided under each NCERT solutions for Class 8 Science will help in understanding the concepts better.

Class 8 Science Chapter 10 Reaching the Age of Adolescence NCERT Questions and Answers - Topics

• 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
→ Muscular Force
→ Friction
• Non-contact Forces
→ Magnetic Force
→ Electrostatic Force
→ Gravitational Force
• Pressure
• Pressure Exerted by Liquids and Gases
• Atmospheric Pressure

Chapter 11 Force and Pressure NCERT Solutions for Class 8 Science  - Notes

• A push or a pull on an object is called a force. Force has magnitude as well as direction.

• The sum of forces acting on bodies is called net force.

• Forces applied on an object in the same direction add to one another. If the two forces act in the opposite directions on an object, the net force acting on it is the difference between the two forces.

• A force
→ may make an object move from rest.
→ may change the speed of an object if it is moving.
→ may change the direction of motion of an object.
→ may bring about a change in the shape of an object.
→ may cause some or all of these effects.

• The force resulting due to the action of muscles is known as the muscular force.

• Force that can be applied only when it is in contact with an object is called a contact force.

• A moving object is called in the state of motion. The force responsible for changing the state of motion of objects in all these examples is the force of friction. It is the force of friction between the surface of the ball and the ground that brings the moving ball to rest.

• The force exerted on an object without touching it is known as non-contact force.

• The force exerted by a charged body on another charged or uncharged body is known as electrostatic force.

• The attractive force of the earth which acts upon all the objects is known as the force of gravity or just gravity. Every object in the universe, whether small or large, exerts a force on every other object. This force is called as the gravitational force.

• The force acting on a unit area of a surface is called pressure. Pressure = force / area on which it acts.

• Atmosphere is the envelop of air all around us is known as atmosphere. The atmospheric air extends up to many kilometres above the surface of the earth.

• Atmospheric Pressure is the pressure exerted by atmospheric air is termed as atmospheric pressure.

Chapter 11 Force and Pressure Class 8 Science Questions and Answers - MCQ Questions with answers

1. What is the cause of change in motion or change in the state of motion?
a) Pressure
b) Atmospheric Pressure
c) Force
d) Friction
► c) Force

2. Force is a
a) Pull
b) Push
c) Pull and push both
d) None of the above
► c) Pull and push both

3. Electrostatic force is exerted by charged body on
a) Another charged body or uncharged body
b) Metallic body only
c) Another uncharged body only
d) Another charged body only
► a) Another charged body or uncharged body

4. Force applied on an object in same direction
a) Divide on another
c) Multiply on another
d) Subtract to one another
► b) Add to one another

5. Perpendicular force acting per unit area is called
a) Power
b) Work
c) Pressure
d) Energy
► c) Pressure

6. The net force on an object is __________ if the two forces acting on it in opposite directions are equal.
a) Always more
b) Towards left
c) Zero
d) Towards right
► c) Zero

7. S.I. unit of force is
a) Pascal
b) Joule
c) Newton
d) Watt
► c) Newton

8. Which of the following effects is caused by frictional force?
a) Change in the shape of an object
b) Change in the direction of the motion of an object
c) Slowing down of a moving object
d) Acceleration in a moving body
► c) Slowing down of a moving object

9. The force between two charged bodies is called
a) Muscular force
b) Gravitational force
c) Magnetic force
d) Electrostatic force
► d) Electrostatic force

10. Which of the following is an example of contact force?
a) Muscular force
b) Gravitational force
c) Electrostatic force
d) Magnetic force
► a) Muscular force

NCERT Solutions is an effective method for learning since you can be le to learn a lot within a short time. You can pinpoint your weaknesses with the help of these NCERT Solutions for Class 8 Science and prepare accordingly to change it in a positive way. It will improve your awareness skills sharply and you can easily memorize more things precisely.