Different forms of energy include light, sound, electrical, elastic, nuclear, magnetic, mechanical (kinetic and potential) and chemical.
Chemical energy is stored in fuel, food and batteries. This energy is released when chemical reactions take place (battery, food).
Kinetic energy is the energy of a moving object (roller coaster, cycle).
Gravitational potential energy is the energy stored in an object due to its position (raised ball).
Elastic potential energy is stored in a springy object when it is stretched, squashed or twisted (elastic).
Electrical energy is energy transferred by an electric current (motor).
Nuclear energy is stored inside atoms (atoms).
The principle of conservation of energy states: energy cannot be created or destroyed; it can only be transferred usefully, stored or dissipated. The total amount of energy does not change.
Energy
Energy is defined as the capacity of a body to do work. The SI unit for energy is the joule (J).
Kinetic energy is the energy possessed by a body by virtue of its motion. The defining equation for kinetic energy is
This equation shows that for two objects with the same mass moving at different speeds, the faster object has greater kinetic energy; and for two objects of different masses but moving at the same speed, the object of greater mass has greater kinetic energy.
Potential energy is the energy possessed by a body by virtue of its position or condition. The gravitational P.E. of a body near the surface of the earth is the product of its weight mg, and its height h, above a reference level e.g. the ground.
