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Doing Work |
Work happens when a force changes the motion of an object. Tossing a ball, writing on paper, riding a bike, and jumping rope are all examples of work. Energy is the ability to do work. Different forms of energy exist. Energy of motion is a form of energy. Stored energy can make an object move. Fuels, batteries, and food are all examples of energy of motion. A toy has batteries so that it can move. A car has fuel which enables it to move.
Calories are used to measure the energy in foods. Heat, light, sound, and electricity are also forms of energy. A toaster that has the bread pushed down is stored energy. Pushing the button releases the spring and causes the bread to pop up.
Baseball is an example of work. Before you swing a bat, your body has stored energy. You use energy to do work to swing the bat. The ball has energy of motion as it comes towards you. The ball that has been hit goes through a change of motion.
Energy can change from one form to another. Rocks rolling down the hill are an example of stored energy changing to energy of motion. Friction changing to heat is another example of energy changing. Rubbing your hands together to create heat is an example of friction.
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