Can thermal energy be made to do useful work?
Thermal energy is/not useful energy that can be used for work.
Plastic 1-liter bottle
Bowl of hot (not boiling) water
Bowl of ice water
- Cool the balloon and the bottle in the freezer for 5 minutes.
- Fill the bowl with hot, not boiling, water.
- Put the balloon over the mouth of the bottle making sure that the air has been squeezed from the balloon. Place the bottle into the hot water.
- The air inside the bottle should expand and inflate the balloon. After it isinflated, put the bottle in the bowl of ice water and observe it deflate.
- Design a device to convert this expansion and contraction into usable work, such as lifting a rock. Design a device that circulates hot, then cold, water so that the balloon deflates and inflates without moving the bottle.
Analysis and Conclusion:
Were you able to make a device that performed useful work? Can you think of devices that convert thermal energy into motion?
Can you think of a way to convert thermal energy into electrical energy? Research internal combustion engines and turbine generators.
Reprinted with the permission of the NEED Project. © 2008 National Energy Education Development Project - All Rights Reserved.
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