Consider two objects of very different sizes that are heated to exactly the same temperature. If we put them into identical containers of cold water, will the effect be the same, or very different?

This activity has a fairly detailed recipe, and will work best if you are careful to follow the instructions.

Materials:

• 3 thermometers
• two rocks of different sizes
• hot water in a large container, to heat the rocks
• cold water
• 3 styrofoam cups
• a "measuring cup" marked so that you can fill the three styrofoam cups equally -- about half full
• There is also a data sheet you can print -- or make your own.

1. Put the rocks in the hot water for about 20 minutes
2. Put equal amounts of cold water into the three cups
3. Measure the temperatures
4. Remove the two rocks from the hot water bath, and shake off the excess water. Put the rocks in separate containers (the third container doesn't get a rock).
5. Start timing right away.
6. After 30 seconds, record the temperature in each container (be sure to stir first!).
7. Starting at one minute, record the temperature every minute for at least 5 minutes, until the temperature stops increasing.
8. Make a graph showing how the temperature of the three containers varied with time. (See the page about graphing for some advice).

It takes energy to raise the temperature of water. According to your results, did your two rocks contain the same amount of thermal energy?

Record your work in your journals, including a discussion of what you learned from this activity.

Check the box when you are done:  

Sharing thermal energy