Blocks, with various surfaces slide on an inclined plane.

Blocks on an Inclined Plane. A Block is placed at the top of the plane, and the plane is tilted until the block just starts to slip. The plane is either wood, or a variable-angle glass inclined plane. All Blocks are 500 grams. Blocks are available with the following surfaces : Smooth soft rubber padding; Hard rubber padding; Sandpaper; Polished bare wood; Ribbed (lateral)rubber padding; Ribbed (longitudinal) rubber padding