PURPOSE: To show the relationship between torque, force, lever arm and angle.

DESCRIPTION: A torque is produced on the two-meter scale by hanging a weight on the right side of the fulcrum. This torque can be balanced by pulling downward with the dynamometer with different forces at various angles on either side of the plumb line.

The photograph at the left shows the torque lever with the protractor in place with its plumb bob and the counterweight on the right. The photographs in the center and at the right show the system balancing the torque created by a weight at the right end of the lever by pulling downward on a spring scale at two angles measured by the protractor.

SUGGESTIONS: Take measurements with the two-meter scale horizontal.

REFERENCES: (PIRA 1J40.25)

EQUIPMENT: Two-meter rigid scale on support fulcrum, 1 kg mass, protractor with plumb bob, counterweight, and 20 Newton spring scale with necessary strings.

SETUP TIME: 10 min.