Work, Energy an...

When a body falls freely under gravity, then the work done by the gravity is:

Raindrops fall on the earth with certain kinetic energy on the earth. From where do they get this energy?

Time rate at which work is done by a force is:

There are two bodies X and Y with equal kinetic energy but different masses m and 4m respectively. The ratio of their linear momentum is:

A truck moves at a steady speed on a horizontal road. What is the work done by the road on the truck? 

Output of a truck is 4500 J and its efficiency is 50%, the input energy provided to the truck is:

By how much does kinetic energy increase if the momentum is increased by 20%?

When a body slides against a rough horizontal surface, the work done by friction is:

 A machine gun fires 60 bullets per minute, with a velocity of 700 m/s. If each bullet has a mass of 50g, find the power developed by the gun.

 If a force acts perpendicular to the direction of motion of a body, what is the amount of work done?