Energy transformations in everyday devices

Energy cannot be made or destroyed, but it can be changed from one form to another. Common forms are electrical, light, heat (thermal), sound, kinetic (movement) and chemical (stored in fuels, food and batteries). Every device takes in energy in one form and gives it out in other forms. We name a device's transformation by its input and its main useful output. Some energy is always lost as heat or sound that we do not want.