Physics Numerical for class 9 motion & other chapters with answers & [PDF]

Last updated on December 12th, 2023 at 01:53 pm

Problems Based on the Conservation of Momentum

54) A boy of mass 50 kg running at 5 m/s jumps onto a 20 kg trolley traveling in the same direction at 1.5 m/s. What is their common velocity?

Solution: solution Q54

55) A girl of mass 50 kg jumps out of a rowing boat of mass 300 kg onto the bank, with a horizontal velocity of 3 m/s. With what velocity does the boat begin to move backward?

Solution: solution Q55

56)A truck of mass 500 kg moving at 4 m/s collides with another truck of mass 1500 kg moving in the same direction at 2 m/s. What is their common velocity just after the collision if they move off together?

Solution: solution Q56

57) A ball X of mass 1 kg traveling at 2 m/s has a head-on collision with an identical ball Y at rest. X stops and Y moves off. Calculate the velocity of Y after the collision.

Solution: solution Q57

58) A heavy car A of mass 2000 kg traveling at 10 m/s has a head-on collision with a sports car B of mass 500 kg. If both cars stop dead on colliding, what was the velocity of car B?

Solution: solution Q58

59) A man wearing a bulletproof vest stands still on roller skates. The total mass is 80 kg. A bullet of mass 20 grams is fired at 400 m/s. It is stopped by the vest and falls to the ground. What is then the velocity of the man?

Solution: solution Q59

60) A metallic sphere of mass 2 kg and volume 2.5 x 10^-4 m³ is completely immersed in water. Find the buoyant force exerted by water on the sphere. Density of water = 1000 kg/m³

Solution: solution Q60