GURUKUL HIGH SCHOOL ROLL NO:
CHAPTER 2: FORCE AND LAWS OF MOTION
NAME:
CLASS: SECTION:
1. A bullet fired against a glass window pane makes a hole in it, and the glass pane is not cracked. But
on the other hand, when a stone strikes the same glass pane, it gets smashed. Why is it so?
2. Describe our walking in terms of Newton’s third law of motion.
3. Explain why does a cricket player moves his hand backward while catching the ball?
4. Two identical bullets are fired one by a light rifle and the other by a heavy rifle with the same force.
Which rifle will hurt the shoulder more and why?
5. When small boy is trying to push a heavy stone, mention various forces acting on the stone.
6. A bullet of 10 g strikes a sand bag at a speed of 103 ms-1 and gets embedded after travelling 5 cm.
Calculate
(i) the resistive force exerted by the sand on the bullet.
(ii) the time taken by the bullet to come to rest.
Page 1 of 4 SCIENCE GRADE 9
GURUKUL HIGH SCHOOL ROLL NO:
7. A body of mass 300 g kept at rest breaks into two parts due to internal forces. One part of mass 200 g
is found to move at a speed of 12 m/s towards the east. What will be the velocity of the other part?
8. The velocity-time graph of a ball moving on the surface of floor is shown in the figure. Calculate the
force acting on the ball, if mass of the ball is 100 g.
9. A bullet of mass 4 g when fired with a velocity of 50 ms-1, can enter a wall up to a depth of 10 cm.
How much will be the average resistances offered by the wall?
10. What is the acceleration produced by a force of 12 newton exerted on an object of mass 3 kg?
Page 2 of 4 SCIENCE GRADE 9
GURUKUL HIGH SCHOOL ROLL NO:
11. A cracker of mass 100 g explodes into two pieces of equal mass. Show that these two pieces of the
cracker fly in opposite direction.
12. An iron sphere of mass 1 kg is dropped from a height of 10 m. If the acceleration of sphere is
9.8 ms-2, calculate the momentum transferred to the ground by the ball.
13. A man throws a ball of mass 0.4 kg vertically upwards with a velocity of 10 m/s. What will be its
initial momentum? What would be its momentum at the highest point of its reach?
14. Which would require a greater force—accelerating a 2 kg mass at 5 ms-2 or a 4 kg mass at 2 ms-2 ?
Page 3 of 4 SCIENCE GRADE 9
GURUKUL HIGH SCHOOL ROLL NO:
15. A bullet of mass 20 g is horizontally fired with a horizontal velocity 150 ms-1 from a pistol of mass 2
kg. What is the recoil velocity of the pistol?
16. A boy of mass 40 kg jumps with a horizontal velocity of 5 ms-1 onto a stationary cart with
frictionless wheels. The mass of the cart is 3 kg. What is his velocity as the cart starts moving?
Assume that there is no external unbalanced force working in horizontal direction.
Page 4 of 4 SCIENCE GRADE 9
