In physics, energy is a fundamental quantity that every physical system possesses. Energy of physical system in a certain given state is defined as the amount of work (W) needed to change the state of the system from some initial position to a specific or final position. Energy is found in different forms: Kinetic energy: the energy of moving objects; Thermal energy: the energy associated with heat; Sound energy: the energy of compression waves; Electrical energy: the energy of moving charged particles; Potential Energy: the energy that an object has due to position; also known as stored energy; Chemical energy: the stored energy of chemical substances; Nuclear energy: the stored energy of the atomic nucleus and Radiant energy: the energy of electromagnetic waves, including light. Energy can be readily transformed from one form into another; for instance, using a battery to power an electrical heater converts chemical energy into electrical energy, which is then converted into thermal energy. Also, energy could be transformed in matter and vice versa as the theory of relativity states.
Learn about saving energy and using electricity and natural gas safely.
Shows and explains the milestones in the history of energy and their uses.
Features stories about several related aspects, current and future energy demands, and ways to conserve energy.
Contains several activities that deal with energy.
Features various sections about energy including what it is and the forms it comes in. Find out how humans use energy through quizzes and a 'fun facts' section.
California Energy Commission's energy and environmental education site for students, parents, and teachers. Offers games, puzzles, and science projects on energy.
Detailed guide explains what energy is and where it comes from.
Information from the U.S. Department of Energy about coal, oil, and natural gas.
Looks at the history of electric power.
Nuclear energy tutorial from the Nuclear Regulatory Commission. Includes nuclear background, reactor design, radiation, emergency planning, decommissioning and related issues.
Look at reasons to use nuclear power, and how it works.
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