Heat Sources - Get Your Motor Running
The sun is not our only source of heat. Many machines will make heat and sometimes light when they are running. Machines that use electricity to run are called electrical machines. Some examples of electrical machines include lamps, TVs, toasters, and all battery-powered toys. Mechanical machines do not use electricity, but may get energy from people, water, horsepower, or even burning fuel (gasoline). Some examples of mechanical machines include car engines, lawn mowers, scooters, bicycles, and scissors.
Look at the pictures below. They are all sources of heat because they get warm as they operate. Notice the pictures on the left are electrical heat sources. That means electricity produces their heat. The pictures on the right are mechanical heat sources. Heat in these objects is produced as movement happens.





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Look around your house or school for other examples of electrical and mechanical heat sources. Remember, if it uses electricity or is battery-powered, it is an electrical machine. All other machines are mechanical.
Is a baseball bat a mechanical machine? Yes! You are the energy source. See if you get warmer after swinging a bat a few times.
Look at your toys to see if they are mechanical or electrical machines.
CAUTION: Some machines can get hot enough to burn you.

