A sphere of mass 20 kg moving with a velocity 40 ms^-1 collides with another sphere of mass 15 kg which is at rest. After collision they move with the same velocity. Find that velocity.

A force of 200 dyne acts on a body of mass 10 g for 5 s. What will be the velocity of the body if it starts from rest? Express in SI unit.

A force of 60 N acts on a body for 10 s. What is the change in momentum?

A body of mass 2 kg moving with uniform velocity of 40 ms^-1 collides with another body at rest. If two bodies move together with a velocity of 20 m^-1, Find the mass of the other body.

A pistol fired a bullet of mass 50 g triggered with a speed 250 ms^-1 penetrated into a wooden plank comes to rest at 1 ms. Find the impulse and average force offered by the planks.