Answer: A lever is a simple machine. A lever bar exerts a force to move a load by turning on a pivot or fulcrum. When the fulcrum is located close to the load, a small force applied to the end of the lever bar farthest away from the fulcrum is magnified so that the lever bar easily moves the heavy load. The force is magnified when the long part of the lever bar moves through a great distance. The short part of the lever bar, located between the fulcrum and the load, moves through a much smaller distance. There are three types of levers: 1st Class, 2nd Class, and 3rd Class. The relative position of the load, fulcrum and force determine the class of lever.     1st Class Lever                  2nd Class Lever                3rd Class Lever Professor Beaker's Learning Lab about Levers: Simple Machines