Pulley Systems
The pulley is a simple machine that consists of a grooved wheel and a rope. Like a lever, it provides a mechanical advantage in lifting a heavy load. Pulleys are used to change the direction of an applied force, transmit rotational motion, or used as a mechanical advantage in either a linear or rotational system of motion.
The most basic pulley is the fixed pulley and the movable pulley: 
Fixed Pulley --------------------------------------------------------->>>
A fixed pulley is a pulley in which the wheel does not move. Fixed pulleys change the direction of the effort force. It does not increase the size of the effort force. The effort force is equal to the resistance force in a fixed pulley
