Cranking with a Genecon

1. Connect the VoltageCurrent probe to your handheld computer. Refer to Technical Hints to see how to set up the VoltageCurrent probe.

2. Locate the parts for your small " heat cell" which consists of a resistor inside a block of aluminum. When you put electrical current through the resistor, it converts the electrical energy into heat and heats up the block of aluminum. The heat cell is placed in insulation to prevent heat loss to the environment.

3. Remove the heat cell from its insulation. Attach the two leads of the Genecon to wires extending from the heat cell. Also connect the voltage leads and the current leads of VoltageCurrent probe to the heat cell. Follow the diagram carefully. Don 't put the heat cell in the insulation yet.

4. Start the software to record power. This measures the electrical power, in watts, that you are supplying to the heat cell with the Genecon.

5. Try cranking at a fairly fast speed and observe the power on your graph. Can you crank at a steady fast rate? Now try to crank at a slower steady rate that produces half as much power.

6. Practice until you can do two rates of cranking, slow and fast, where the faster rate produces twice as much power as the slower rate. Stop collecting data and disconnect the voltage and current leads. What is the power of each rate in watts?

7. Connect the Temperature probe to your handheld computer. Refer to Technical Hints to connect the Temperature probe. The sensitive part is just the very tip, where two wires are welded together.

8. Put the tip of the Temperature probe into the small hole in one end of the heat cell.

9. Set the heat cell in the insulation and close up the box with a rubber band.

10. Attach the two Genecon leads to the wires extending from the heat cell.

11. Start the software for the Temperature probe. Start recording temperature.

12. Observe the temperature graph. After 10 seconds, crank the Genecon for 30 seconds at the fast rate. Then crank the Genecon for 30 seconds more at the slower rate. Then stop cranking and continue recording for another 60 seconds.

13. Stop recording the data. Save your data to the handheld.

14. Expand the graph so that you can see how much the temperature rose while you were cranking, and how much it fell after you stopped. oRecord these values in Notes:

    1. starting temperature

    2. the temperature after fast cranking

    3. after slow cranking

    4. the ending temperature

15. Calculate these values in Notes:

    1. the temperature change during fast cranking

    2. the temperature change during slow cranking

    3. the temperature change while cooling

16. The heat cell is made so that it takes exactly 10 joules of energy to heat it one degree Celsius. How many joules did your 30 seconds of fast cranking produce? What about the 30 seconds of slow cranking? How many joules did the cell lose in 60 seconds as it cooled? Record your answers in Notes on your handheld computer.