PURPOSE: To demonstrate mechanical power.

DESCRIPTION: A one-half kilogram mass provides a force of about 5 Newtons hanging over the pulley. Under the specially selected 5 Newton force the wooden box moves at a nearly constant speed. The distance and time can be measured and the power calculated.

Add small masses to the wooden box or to the pulley weight to adjust the motion as necessary.

SUGGESTIONS: Clean table top for best results.

REFERENCES: (PIRA unknown.)

EQUIPMENT: Wooden box, rope and pulley assembly, half-kilogram mass, scale, timer, and box of adjusting masses.

SETUP TIME: 5 min.