Skip to main content
PIRA Code(s)
Set up time
5 minutes
Physics and Science Concepts
Equilibrium of forces, Mechanics, Work and Energy
Set the empty friction box on the incline with weights attached to the string on the other side of the pulley so that the box slides forward. Then, gradually increase the angle of the plane until the box and the weights reach equilibrium.

Given an angle of inclination a of the inclined plane, this apparatus demonstrates that the mass m required to hold a low friction box of mass M at equilibrium on the inclined plane is given by:

mg = Mg sin a