Physics 132 Weeks 9 and 10
Specific Heat
Specific Heat Comparison
When two objects are heated by the same source for the same amount of time some students may believe that they should be the same temperature. Use this demonstration to show them that the material's specific heat influences how quickly it heats up!
Air and Water-Filled Balloons
This demonstration is another fun one that will keep your students engaged. Show them that the specific heat of water is quite large and why water takes so long to change temperature. Practice getting a water and air balloon before trying it in front of your students.
Thermodynamic Engines
Drinking Birds
Many people are familiar with these classic desk toys, and they are a great tool to help discuss how thermodynamic processes can drive motion. Make sure that the bird's head is thoroughly saturated, and try not to bend the aluminum supports.
Stirling Engine
This is a true heat engine, driven solely by a temperature differential. It works on a fairly small temperature difference, but by using the coffee heater and an ice cube to help it start you can engage it quickly.
Steam Engine
This compact steam engine is an exciting and engaging demonstration for any classroom. Once students see how thermodynamic processes are used to spin the fly wheel, you can extrapolate this to most power plants and generators.
Thermoelectric Fan
Another example of a true heat engine, this is driven solely by temperature difference. The fan requires a noticeable temperature difference and may need a small nudge. Show students that the fans spin the opposite direction by placing a second fan's legs in opposite temperatures.
Crook's Radiometer
The vanes on the radiometer are colored differently on each side. The black side will heat up more rapidly than the white side causing the vane to spin. See if your students can explain why the vane rotates knowing that it is not an example of the photoelectric effect.