PURPOSE: To show the mechanical equivalent of heat.
DESCRIPTION: A hollow tube is 1 meter in length and contains .5 Kg of lead shot, as shown in the above photo. When the tube is inverted the amount of work is equal to .5 Kg of lead falling the distance of 1 meter. By repeatedly inverting the tube the temperature of the lead shot can be made to rise above room temperature. It is suggested the tube be passed around among the students, each student in turn inverting the tube.
After 30 to 50 inversions the temperature of the lead shot will rise about 10 degrees above room temp. The temperature of the lead shot is measured with a digital thermometer attached to a large classroom display meter.
EQUIPMENT: Tube with lead shot, as photographed. Thermometer and display meter.
Updated by JZ 6/20/2000