# Law of Conservation of Mechanical Energy

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Law of conservation of mechanical energy states the total mecanical energy in a system remains constant as long as the only force acting are conservative forces.

### Law of conservation of mechanical energy formula

$$\large{ PE_i + KE_i = PE_f + KE_f }$$

Where:

$$\large{ KE_f }$$ = final kinetic energy

$$\large{ PE_f }$$ = final potential energy

$$\large{ KE_i }$$ = initial kinetic energy

$$\large{ PE_i }$$ = initial potential energy

Tags: Equations for Energy