Question

derivation for potential energy

Answer 1

work done=force *displacement
mg * height
=mgh

Answer 2

Potential energy of a body is the work done to take the body to a particular height. Let a body having mass m is raised to a particular height h, then the gravitational force acting on the body of the earth is m*g (which acts downwards). So the work done against he gravity will be-
Work done = F*s , where F stands for Gravitational force and s stands for displacement
Work done = mg*h
Work done = mgh
Hence,
Potential Difference = mgh