The+Law+of+Conservation+of+energy

=﻿The Law of Conservation of Energy=

What does the Law of Conservation of Energy state?
 * This law states that energy can not be created or destroyed, therefore the sum of all the energy in a system is constant.

The most common example of using the Law of Conservation of Energy is a pendulum.



To Calculate the Potential Energy of this, you use the formula **PE = mgh** Example 1: If the mass of the ball is 10kg, the height is 0.2m, and gravity is 9.8m/s^2. What is the potential energy in the pendulum?

PE = mgh = (10kg) (9.8m/s^2) (0.2m) = 19.6 J

The position of the blue ball has 19.6 J of energy, while kinetic energy is 0. When the blue ball moves toward the purple ball, potential energy is decreasing and kinetic energey is increasing. When the ball is exactly in the middle (position of the purple ball) kinetic energy and potential energy is equal. If the ball keeps going, potential energy, once again, increases and kinetic energy will eventually be back at zero.

Formulas:
 * PE = mgh ( Potential Energy = mass x gravity x height )
 * KE = ½ mv^2 ( Kinetic Energy = ½ x mass x velocity ^2 )
 * KE + PE = KE' + PE' ( ½ mv^2 + mgh = ½ mv^2' + mgh' )
 * KE + PE = KE' + PE' + Ef ( ½ mv^2 + mgh = ½ mv^2' + mgh' + Energy )
 * P = W / t ( Power = Work / time )