Simple Machines Simple Machines Machines are mechanical devices that help do work.
Machines redirect or change the size of forces, thus making work easier.
The pully is a lever that rotates around a fixed point. Pulleys are often used to redirect forces rather than increase them. The inclined plane or ramp is the simplest of all machines. The longer the inclined plane, the smaller the necessary input force. The inclined plane allows a person to do less work in moving a heavier object.