Inclined Plane - Friction Box And Weights
To show that the coefficient of friction does not depend upon the mass of the object although the frictional force does.
Inclined plane, friction box, weight set, as photographed.
Set the empty box on the incline and increase the angle until sliding ensues. Add weights to the box and repeat the experiment. The weighted box begins to slide at the same angle.
Margaret Stautberg Greenwood, Inclined Plane on a Frictionless Surface, TPT 28, 110 (1990). William M. Wehrbein, Frictional forcs on an inclined plane, AJP 60, 57-58 (1992). Jonathan Mitschele and Matthew Muscato, Demonstration Normal Forces with an Electronic Balance, TPT 32, 555-556 (1994).