What is potential energy ? Derive an expression for the gravitational potential energy .

Explanation

Potential energy : Definition : The energy possessed by a body by virtue of its position of state is called potential energy
e.g. : (1) Energy possessed by water stored in a dam
A stretched rubber card
Formula for P.E = mgh : The potential is measured by the work done is lifting a body through a height .h. against gravitational force.
Consider a body of mass m on the body against gravitational force .
` :.` Gravitational force F = Weight of the body
Minimum force needed to left the body = F in upwards direction F = mg
Height lifted =h
Work done W = gravitational force `xx` height lifted
W = mgh
This work done done is stored as potential energy .
`:.` Potential energy P.E = mgh