Changing Energy

Energy can be transformed into another form of energy. But it cannot be created or destroyed. Some changes in energy from one form to another include:

Stored energy in a flashlight's batteries becomes light energy when the flashlight is turned on.

Food is stored energy. It is stored as a chemical with potential energy. When your body uses that stored energy to do work, it becomes kinetic energy. If you overeat, the energy in food is not "burned" but is stored as potential energy in fat cells.

When you talk on the phone, your voice is transformed into electrical energy, which passes over wires (or is transmitted through the air). The phone on the other end changes the electrical energy into sound energy through the speaker.

A car uses stored chemical energy in gasoline to move. The engine changes the chemical energy into heat and kinetic energy to power the car.

A toaster changes electrical energy into heat and light energy. (If you look into the toaster, you'll see the glowing wires.)

A television changes electrical energy into light and sound energy.

What Is Energy?
Energy Basics
Changing Energy
Energy Conversion Efficiency


Go to Topic 2. Renewable Energy Sources