This document defines energy as the ability to do work and cause changes in matter. It lists several forms of energy including heat, light, electrical, sound, and chemical energy. Potential energy is described as stored energy with the ability to change into another form to do work or cause changes. Fuel is a source of potential energy with examples including fossil fuels which get their energy from sunlight, as well as batteries. The document explains that potential energy can change into kinetic energy, which is the energy of motion, with examples being a car burning gasoline to move or a skier skiing downhill.
