Energy conservation

Science

Definition

The principle that energy cannot be created or destroyed, only transformed from one form to another. In any closed system, the total energy remains constant. This is also known as the first law of thermodynamics.

Examples

  • A roller coaster converting potential energy at the top of a hill into kinetic energy at the bottom
  • A pendulum swinging back and forth between kinetic and potential energy
  • Chemical energy in food being converted to thermal energy and mechanical energy in your body
Key Fact

ΔE_system = 0 in an isolated system; energy in = energy out

Related Terms

Conservation of energy Kinetic energy Potential energy Work-energy theorem

Study This Concept

Practice energy conservation with free review games in these units:

AP Environmental Science Unit 6: Energy Resources and Consumption