Conservation of energy is the law of physics that states energy can neither be created nor destroyed, but can be converted from one form to another. Examples of conservation of energy include a moving car losing kinetic energy as it slows down and a battery gaining electrical energy as it is charged. When energy moves from one form to another, the total amount of energy in the system does not change. Another example is a see-saw, where the energy of a person sitting up is transferred to the other person down low when the lever is balanced.