Kinds of Simple Machines
Lever
Classes of lever
There are three classes of levers.
In a first-class lever, the fulcrum (F) is between the resistance force (R) and the effort force (E). Examples of first-class levers are seesaws, crowbars, pliers, scissors, and hammers.
In a second-class lever, the resistance force (R) is between the fulcrum (F) and the effort force (E). Examples of a second-class lever are nutcrackers, bottle openers, and wheelbarrows.
In a third-class lever, the effort (E) is between the fulcrum (F) and the resistance force (R). Examples of third-class layers are baseball bats, test tube holders, tongs, shovels, and brooms.
