Heating with a light bulb

1. Let's find out how a mini light bulb compares to a heat cell as an electrical heating device. Connect the Temperature probe to your handheld computer. Refer to Technical Hints to connect the Temperature probe.

2. Divide the student research teams into two groups. Half the teams will surround the mini light with clear tape, and the other half will surround it with aluminum foil.

• Tape teams: Hold the tip of the Temperature probe against the mini light with a short piece of clear tape that goes right around the bulb.

• Foil teams: Wrap the mini light with a small piece of aluminum foil that goes all the way around it. Hold the foil in place with a short piece of clear tape. Slide the tip of the Temperature probe in between the bulb and the aluminum foil.

3. Attach one lead of the battery to the mini light, but not the other.

4. Start the software to record temperature.

5. Attach the second battery lead and light up the mini light.

6. Monitor the temperature plot. Let it run for 30 seconds, then disconnect the second lead and let it run for another 30 seconds. Stop recording.

7. Stop recording the data. Save the data to your handheld computer.

8. Expand the graph so that you can see how much the temperature rose while the battery was attached and how much it decreased after you stopped. Record these values in Notes:

   1. the starting temperature

   2. the maximum temperature

   3. the ending temperature

9. How many degrees did the light heat up in 30s? How many degrees did it cool down in 30s? Record these values in Notes on your handheld computer.