Four Surface Incline (1K20.10)

Description:

A board is covered with strips of four different materials (Teflon, sandpaper, bare wood, and rubber) that run down the length of the board. Identical brass blocks are placed at the end of each, and the end of the board near the blocks is slowly lifted up. As the angle increases, the blocks will slide down the strip in order of the different coefficients of friction.