Potential energy (PE)

The energy possessed by body or system by virtue of its position above the datum level. The work done is because of its falling on earth's surface.

Potential energy, PE = Wh = mgh N.m

Where, W = weight of body, N ; m = mass of body, kg h = distance of fall of body, m

g = acceleration because of gravity, = 9.81 m/s²

Kinetic Energy (KE)

The energy possessed by a system by virtue of its motion is called kinetic energy. It means that system having of mass m kg while moving with a velocity V1 m/s, does 1/2mV12 joules of work sooner than coming to rest. So in the state of motion, system is said to have a kinetic energy given as;

K.E. = 1/2mv_1²

However, when the mass undergoes a change in its velocity from velocity V1 to V2, the change in kinetic energy of system can be expressed as;

K.E. = 1/2mv₂² - 1/2mv₁²