Students know electrical energy can be converted to heat, light, and motion.

A major feature of energy is that it readily changes from one form to another. Rub your hands together and you will notice the conversion of motion energy to heat. You were able to rub your hands because your body converted the chemical energy in food into motion energy. These kinds of changes in the forms of energy happen within and outside us all the time.

The topic of electricity provides many examples of energy changing forms. An incandescent light bulb gets very hot because of the electricity flowing through it. It gets so hot that it glows. Thus, in a light bulb, electric energy is changing to heat and light. An electric heater, oven, clothes dryer or a clothes iron provide examples of devices that maximize the conversion of electricity to heat.

Many household appliances and devices focus on converting electricity to motion. Obvious ones include electric beaters, blenders, or toothbrushes. Other devices that include electromagnets in their internal mechanism also involve converting electric energy to motion. Examples include doorbells (see CONTENT TIP 1d) and speakers/earphones (these have vibrating components that make the sounds we hear).