Potential energy is given by

V = mgh

Where,

m = mass of the body.

h = height of that body.

g = acceleration due to gravity.

## Kinetic energy

Kinetic energy of a moving body is given by following formula,

K.E. = 1/2 ( mv^{2} )

or K.E. = p^{2}/2m

Where,

m = Mass of the moving body.

v = Velocity of that body.

p = Linear momentum of that particle.

## Mechanical energy

The mechanical energy ( E ) of a body is given by,

E = K + V

E = 1/2 (mv^{2}) + mgh

Where,

K = Kinetic energy of a body.

V = Potential energy.

m = mass of a body.

v = velocity of that body.

g = acceleration due to gravity.

h = height of a body.

## What is the energy?

The capacity to do work is called energy.

Energy is a scalar quantity. The dimensional formula of the energy are the same as the dimensional formula of work i.e. [ M^{1}L^{2}T^{-2} ].

SI unit of energy is joule and CGS unit of energy is erg.

### Characteristics of energy

- The entire matter possesss energy.
- Energy can neither be created nor be destroyed. The quantity of energy in the universe is constant
- Energy can be transformed from one form to the other.