# MCQ Questions Chapter 9 Force And Laws Of Motion Class 9 Science

Please refer to MCQ Questions Chapter 9 Force And Laws Of Motion Class 9 Science with answers provided below. These multiple-choice questions have been developed based on the latest NCERT book for Class 9 Science issued for the current academic year. We have provided MCQ Questions for Class 9 Science for all chapters on our website. Students should learn the objective based questions for Chapter 9 Force And Laws Of Motion in Class 9 Science provided below to get more marks in exams.

## Chapter 9 Force And Laws Of Motion MCQ Questions

Please refer to the following Chapter 9 Force And Laws Of Motion MCQ Questions Class 9 Science with solutions for all important topics in the chapter.

MCQ Questions Answers for Chapter 9 Force And Laws Of Motion Class 9 Science

OBJECTIVE QUESTIONS

Question. A men is at rest in the middle of a pond on perfectly smooth ice. He can get himself to the shore by making use of Newton’s
(a) first law
(b) second law
(c) third law
(d) all the laws

C

Question. A number of forces acting on a body changes velocity of the body. The forces cannot be
(a) paralleled
(b) unbalanced
(c) balanced
(d) inclined

C

Question. Newton’s second law of motion gives us a measure of
(a) force
(b) inertia
(c) mass
(d) acceleration

A

Question. Choose the correct statement(s).
(a) Action and reaction forces act on same object.
(b) Action and reaction forces act on different objects.
(c) Both a and b are possible.
(d) Neither a nor b is correct.

B

Question. The momentum of an object at a given instant is independent of its
(a) inertia
(b) mass
(c) velocity
(d) acceleration

D

Question. A body at rest explodes into two equal parts. Then
(a) they move with different speeds in different directions
(b) they move with different speeds in same direction
(c) they move with same speed in same direction
(d) they move with same speed in opposite directions

D

Question. Read the given statements and select the correct option.
Statement 1 : The forces of action and reaction always appear due to actual physical contact of two bodies.
Statement 2 : A particle can move only under the action of a force.
(a) Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
(b) Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
(c) Statement 1 is true but statement 2 is false.
(d) Both statements 1 and 2 are false.

D

Question. A man is standing on a boat in still water. If he walks towards the shore the boat will
(a) move away from the shore
(b) remain stationary
(c) move towards the shore
(d) sink

A

Question. Galileo’s law of inertia is another name for Newton’s ………. law of motion.
(a) first
(b) third
(c) second
(d) none of these

A

Question. Newton’s third law is equivalent to the
(a) law of conservation of linear momentum
(b) law of conservation of angular momentum
(c) law of conservation of energy
(d) law of conservation of energy and mass

A

Question. A rider on horse falls back when horse starts running, all of a sudden because
(a) rider is taken back
(b) rider is suddenly afraid of falling
(c) inertia of rest keeps the upper part of body at rest while lower part of the body moves forward with the horse
(d) none of the above

C

FILL IN THE BLANK

Question. The change in the momentum of an object is equal to the ……….. applied to it.

impulse

Question. When a running car stops suddenly, the passengers are jerked ……….

forward

Question. Impulse is the product of force and ………

Time

Question. To every action, there is an ………. and ………. reaction.

equal, opposite

Question. If a force of 200 newtons is required to move a wagon up a frictionless hill at constant speed the force needed to left the wagon roll downhill at constant speed is ……….

200 Newtons

Question. ………. is a measure of the inertia of a body.

mass

TRUE/FALSE

Question. No net force acts on a rain drop falling vertically with a constant speed.

True

Question. When we push our foot against the ground backwards (action), the ground exerts an equal and opposite force (reaction) on our foot which causes us to more forward.

True

Question. Particle moves in the direction of force.

False

Question. Momentum is never created nor destroyed.

True

Question. The product of the mass of a body and its velocity is called inertia.

False

MATCHING QUESTIONS

Question.

(A) (q), (B) p, (C) t, (D), r, (E) s

ASSERTION AND REASON

Question. Assertion : Newton’s third law applies to all types of forces. e.g. gravitational, electric or magnetic forces etc.
Reason : Newton’s third law of motion is applicable only when bodies are in motion.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

C

Question. Assertion : A rocket works on the principle of conservation of linear momentum.
Reason : For two bodies system when there is a change in momentum of one body, the same change occurs in the momentum of the second body but in the opposite direction.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

Question. Assertion : When astronauts throw something in space, that object would continue moving in the same direction and with the same speed.
Reason : The acceleration of an object produced by a net applied force is directly related to the magnitude of the force, and inversely related to the mass of the object.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

B

Question. Assertion : Mass is a measure of inertia of the body in linear motion.
Reason : Greater the mass, greater is the force required to change its state of rest or motion.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

Question. Assertion : Linear momentum is conserved in both elastic and inelastic collisions.
Reason : Total energy is conserved in all collisions.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

B

Question. Assertion : A body is momentarily at rest when it reverses the direction.
Reason : A body cannot have acceleration if its velocity is zero at a given instant of time.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

C

Question. Assertion : When we sit on a chair, our body exerts a force downward and that chair needs to exert an equal force upward or the chair will collapse.
Reason : The third law says that for every action there is an equal and opposite reaction.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

A

Question. Assertion : A boy facing forward in a moving bus throws a ball straight up. At the same instant the bus begins to accelerate. The ball goes up and falls in front of the boy.
Reason : As the ball rises, velocity remains constant.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

D

Question. Assertion : Force exerted by the ground on the man moves him forward.
Reason : It is a reactional force.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.

B

Question. Assertion : When a bullet is fired from a gun, there is a forward force on the bullet and recoil of gun.
Reason : Every action has an equal and opposite reaction.
Options:
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both Assertion and Reason are false.