# 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 Q5**5

**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 Q5**6

**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}** ** m^{3}** is completely immersed in water. Find the buoyant force exerted by water on the sphere. Density of water = 1000 kg/m**^{3}

**Solution: solution Q60**

I find this collection of physics problems very useful. Our class teacher has also prescribed us to solve these problems. Thank you.

Many thanks for putting in the effort for students like me. I am solving these problems even for the competitive exams I will have soon.

You have a good amount of materials for physics problems. I found this site very helpful. One request: can you post chemistry problems as well?

Thanks for your comments and suggestion, Shilpa. We will certainly plan for it.

Hi Ayan, Good to know this. Best wishes.

Thanks Dip for your inspiring words.