Explanation of Conservation of Mechanical Energy

giorgiana1976 | Student

The sum of the potential energy and kinetic energy (i.e. mechanical energy) of a system of particles remains constant during the motion, under the action of the conservative forces.

Work done = change in its kinetic energy

W = Ek2 - Ek1 (1)

Work done is equal to negative change of potential energy

W = -(Ep2 - Ep1) (2)

We'll put (1) = (2):

Ek2 - Ek1 = -(Ep2 - Ep1)

Ek2 + Ep2 = Ek1 + Ep1