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 ( mv2 )
or K.E. = p2/2m
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 (mv2) + 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. [ M1L2T-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.