This simple machine is made up of a wheel and a rope. The rope fits on the groove of the wheel.

One part of the rope is attached to the load. When you pull on one side of the pulley, the wheel turns and the load will move. Pulleys let you move loads up, down, or sideways. Pulleys are good for moving objects too hard to reach places. It also makes the work of moving heavy loads a lot easier.
Examples of where pulleys can be used: Flag Poles; Clothes Lines; Sailboat; Blinds; Crane.

Purpose of Pulleys: Pulleys are used to transfer force or speed to turn another pulley connected by a belt. There are different fixed(single) and connected(two or more) pulleys.

1. The pulley you turn (called the driver) causes the other pulley (called the follower) to turn also, because they are connected by a belt. The driver and the follower turn in the same direction.
2. The driver and the follower turn in the opposite direction when connected by a crossed belt.
3. A small driver makes a large follower turn slower (referred to as gearing down), which decreases the speed of rotation but increases the force.
4. A large driver makes a small follower turn faster (referred to as gearing up), which increases the speed of rotation but decreases the force.
5. A belt drive can be used to change the direction of rotation by 90 degrees.
6. A fixed pulley can change the direction of a lifting force to a more convenient angle.
7. A movable pulley can be used with a fixed pulley to lift a load with less effort than with a fixed pulley alone.