Forms of Energy

Energy is what makes things happen. It moves objects, lights up rooms, warms our food, and lets us hear sounds. Energy never disappears — it only changes from one form into another.

The Main Forms of Energy

• Kinetic energy — the energy of anything that is moving.
• Potential energy — stored energy waiting to be released.
• Thermal energy — heat energy from particles moving inside a substance.
• Light energy — energy you can see, given off by the sun, lamps, and fire.
• Sound energy — energy that travels as vibrations through air, water, or solids.

Kinetic vs. Potential

A roller coaster is a perfect example. As it climbs the first hill, it builds up potential energy. The higher it goes, the more energy is stored. When it drops, that potential energy quickly turns into kinetic energy as the cars race down the track.

• A book on a high shelf has potential energy.
• The same book falling toward the floor has kinetic energy.
• A stretched rubber band has potential energy.
• A flying paper plane has kinetic energy.

Energy Changes Form

• A flashlight changes electrical energy into light energy.
• A campfire changes chemical energy in wood into thermal and light energy.
• A drum changes the kinetic energy of your hand into sound energy.
• A solar panel changes light energy into electrical energy.