ABSTRACT
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. A force may be applied to the block which is insufficient to move it. In this case, the force resisting motion is called the static friction or stiction. Thus there are two categories into which a frictional force may be split:
(i) dynamic or sliding friction force which occurs when motion is taking place, and
(ii) static friction force which occurs before motion takes place.
