Energy: it changes form, it does not disappear · Pulse Beat
Energy comes in forms: movement (kinetic), height (gravitational potential), heat, light, sound, chemical, electrical. It changes from one form to another, and in a closed system the total stays the s
Energy comes in forms: movement (kinetic), height (gravitational potential), heat, light, sound, chemical, electrical. It changes from one form to another, and in a closed system the total stays the same. This is the conservation of energy.
A pendulum shows it. At the top of its swing it is momentarily still and has the most potential energy. At the bottom it moves fastest and has the most kinetic energy. Each swing it loses a little to air and friction as heat, so it slowly stops.
The formulas: kinetic energy = ½ m v². Gravitational potential energy near Earth = m g h. Doubling speed quadruples kinetic energy, which is why speed matters so much in a crash.
Energy is measured in joules. Power is energy per second, measured in watts.