1. pulley

2. What is a pulley?
Answer: A pulley is a simple machine that consists of a wheel with a groove in it and a cord that fits into the groove. A load is attached to one end of the cord and the input force is applied to the other end of the cord.

3. How do different types of pulleys make work easier?
Answer: A fixed pulley changes the direction of the input force, but it does not change the strength of the input force. For a fixed pulley, the output force is the same as the input force. A moveable pulley increases the output force compared to the input force, but it does not change the direction of force. A compound pulley is a system of fixed and moveable pulleys, and it can change both the direction of force and strength of the force.

4. How can pulleys be used together in a system to increase mechanical advantage?
Answer: Mechanical advantage is the ratio of output force to input force. If pulleys are added to a system correctly, each additional pulley can increase the mechanical advantage of the system. When added correctly, the ropes attached to each pulley help support the load and reduce the force needed to lift the load.