Define potential energy. Write the SI unit of potential energy. Derive an expression for potential energy.

Potential energy

The energy of a body due to its position or change in shape is known as Potential Energy.
Derivation
Suppose a body of mass m is raised to a height h above the surface of the earth. The force acting on the body is the gravitational pull of the earth m × g which acts in the downward direction. To lift the body above the surface of the earth, we have to do work against this force of gravity,
Now,
Workdone = Force × Distace
So, W = m × g × h
This work gets stored up in the body as potential energy.
Thus, Potential Energy = m × g × h
Where m = mass of the body
g = acceleration due to gravity
h = height of the body
SI unit of Potential Energy is Joule

Question Asked on July 30, 2015, 5:25 p.m. by Akshay