Class 1, Class 2, Class 3
- Class 1: Fulcrum in the middle: the effort is applied on one side of the fulcrum and the resistance on the other side, for example, a crowbar, or a pair of scissors
The fulcrum is located at the middle.
The fulcrum is located at one side and the load is in the middle.
The fulcrum is located on one side with the load on the opposite side.
Fulcrum in middle with two equal loads being used for the effort.
Load in the middle with effort on one side, and fulcrum on the other side.
Effort in the middle with fulcrum on one side and the load is being manipulated.
The Law of Equilibrium.
A lever is in equilibrium when the effort and the load balance each other. The law of equilibrium is: The effort multiplied by its distance from the fulcrum equals the load multiplied by its distance from the fulcrum. This law of equilibrium is true for all classes of levers.