# MCQ Questions for Class 9 Science Chapter 9 Force and Laws of Motion

Solving the Force and Laws of Motion Multiple Choice Questions of Class 9 Science Chapter 9 MCQ can be of extreme help as you will be aware of all the concepts. These MCQ Questions on Force and Laws of Motion Class 9 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Have a glance at the MCQ of Chapter 9 Science Class 9 and cross-check your answers during preparation.

Multiple Choice Questions

Question 1.
Rocket works on the principle of conservation of:
(a) mass
(b) energy
(c) momentum
(d) velocity

Question 2.
Among the equal-sized stone and a football, the inertia will be higher of:
(a) football
(b) stone
(c) both
(d) none of them

Question 3.
A batsman hits a cricket ball which then rolls on the ground. After covering a short distance, the ball comes to rest. The ball slows to a stop because:
(a) the batsman did not hit the ball hard enough.
(b) velocity is proportional to the force exerted on the ball.
(c) there is a force on the ball opposing the motion.
(d) there is no unbalanced force on the ball so the ball would want to come to rest.

Answer: (c) there is a force on the ball opposing the motion.

Question 4.
What is the momentum of an object of mass m, moving with a velocity v?
(a) (mv)2
(b) mv2
(c) $$\frac{1}{2}$$ mv2
(d) mv

Question 5.
Friction is:
(a) useful to us
(b) harmful to us
(c) both useful as well as harmful to us
(d) none of them.

Answer: (c) both useful as well as harmful to us

Fill in the Blanks.

Question 6.
The SI unit of momentum is _________.

Question 7.
The natural tendency of objects to resist a change in their state of rest or of uniform motion is called ______

Question 8.
To every action, there is an ______ and opposite reaction.

Question 9.
The resultant force of balanced forces is ________

Question 10.
The force can change the motion, direction, or _______ of an object.

Question 11.
The value of inertia depends on the _______ of an object.

Question 12.
The rate of change of momentum of an object is ______ to the applied unbalanced force in the direction of the force.

True/False.

Question 13.
In 1586, Galileo Galilei wrote his first scientific book ‘The Little Balance’.

Question 14.
In practical situations, it is difficult to achieve a zero balanced force.

Question 15.
Force is a scalar quantity.

Question 16.
The mass of an object is a measure of its inertia.

Question 17.
In an isolated system, the total momentum remains conserved.

Match the Column.

Question 18.

 A B 1. Unit of force (i) Mass × acceleration 2. Unit of pressure (ii) kgms-1 3. Test of purity of milk (iii) Pascal 4. Force (iv) Lactometer 5. S.I unit of momentum (v) Newton

 A B 1. Unit of force (v) Newton 2. Unit of pressure (iii) Pascal 3. Test of purity of milk (iv) Lactometer 4. Force (i) Mass × acceleration 5. SI unit of momentum (ii) kgms-1

Question 19.
Write the unit of pressure.

Question 20.
A body is moving with constant velocity, then what will be the acceleration of that body?

Question 21.
Write the S.I unit of force.

Question 22.
On what factor the inertia of an object depends?

Question 23.
Express the second law of motion of newton in the context of the equation of momentum.

Answer: Force = $$\frac{\text { Change in momentum } \Delta P}{\text { time }}=\frac{m(v-u)}{t}$$