The ability of a body to do work when its normal position or configuration is changed to some other position or configuration is called potential energy.
To use the potential energy stored in a body it is necessary to transform it into other forms of energy. For example, a piece of stone is not dangerous as long as it is on the roof and its potential energy transforms into kinetic energy i.e. it starts to fall.
What will be the potential energy of a body of mass 6kg if it is raised to a height of 20m above the surface of the earth? g = 9.8 ms-2.
Mass of the body, m = 6 kg
Height, h = 20m
g = 9 8 ms-2
Potential Energy, Ep = ?
Ep = mgh
= 6 kg x 9.8 ms-2 x 20 m = 1176 J
Ans: 1176 J