Energy

Energy has different meanings in different contexts. In layperson's terms energy can be defined as the measure of potential to bring changes in a system. In physics parlance, energy refers to capacity of doing work. Energy can occur in various forms: kinetic, potential, electromagnetic, sound, and so on. Energy of a moving car is kinetic energy, where [Page 567]as the energy of water stored in a dam is potential energy. Energy can be converted from one form to another. For example, when water falls from a dam, the potential energy of water gets converted into kinetic energy, which drives turbines to produce electrical energy. When a car crashes into a wall, the kinetic energy of the car is converted into heat and sound energy. When ...