Class 9 Science Force and Motion
Class 9 Science Force and Motion Fill in the blanks , Multiple Choice Question [mcq] and True false .
Fill in the Blanks
1. Force is a ______, hit or pull.
Ans: push
2. ______ force changes the motion of an object.
Ans: Unbalanced
3. The tendency of objects to stay at rest or keep moving is called ______.
Ans: inertia
4. The SI unit of force is ______.
Ans: newton (N)
5. Friction always acts in the ______ direction of motion.
Ans: opposite
6. Mass is a measure of ______.
Ans: inertia
7. Momentum = mass × ______.
Ans: velocity
8. To move a big object, we need more ______.
Ans: force
9. A moving object will keep moving unless a ______ force acts on it.
Ans: unbalanced
10. The third law of motion is – For every action, there is an ______ and opposite reaction.
Ans: equal
11. A moving ball slows down due to ______.
Ans: friction
12. Newton’s first law is also called the law of ______.
Ans: inertia
13. A heavier object has more ______ than a lighter one.
Ans: inertia
14. The force needed to change motion depends on ______ and acceleration.
Ans: mass
15. The SI unit of momentum is ______.
Ans: kg m/s
Multiple Choice Questions
1. What does force do to an object?
(a) Changes shape
(b) Changes speed
(c) Changes direction
(d) All of these
Ans: (d) All of these
2. Inertia depends on:
(a) Shape
(b) Size
(c) Mass
(d) Speed
Ans: (c) Mass
3. Which of the following has more inertia?
(a) A rubber ball
(b) A stone of same size
Ans: (b) A stone of same size
4. Newton’s First Law explains:
(a) Momentum
(b) Inertia
(c) Gravity
(d) Force
Ans: (b) Inertia
5. What is the SI unit of force?
(a) kg
(b) m/s
(c) N
(d) km/h
Ans: (c) N
6. A football slows down because of:
(a) Speed
(b) Force
(c) Friction
(d) Mass
Ans: (c) Friction
7. What happens when a bus suddenly stops?
(a) You fall backward
(b) You fall forward
Ans: (b) You fall forward
