This apparatus is used to measure the co-efficient of friction of different materials at different angles. The friction increases due to the roughness of surfaces.
The unit consists of a plane surface which has a pulley at its one end. The plane can be set to any angle with the help of pointer and protector. Blocks of different materials are available with this apparatus. A cord is tied to the block and at the other end of cord, a hanger is tied. The cord is passed over the pulley and weights are placed in the hanger so that the block starts moving.