ABSTRACT
This chapter explains, both dynamic and static frictions, together with the factors that affect the size and direction of frictional forces. When an object, such as a block of wood, is placed on a floor and sufficient force is applied to the block, the force being parallel to the floor, the block slides across the floor. When the force is removed, motion of the block stops, thus there is a force which resists sliding. This force is called dynamic or sliding friction. The coefficient of friction is a measure of the amount of friction existing between two surfaces. The coefficient of friction is the ratio of a force to a force, and hence has no units. A low value of coefficient of friction indicates that the force required for sliding to occur is less than the force required when the coefficient of friction is high.
