FIRST CLASS LEVER Why are there three classes? There are three classes of levers because all are classified by the locations of the fulcrum, the input force, and the output force.
Key Terms: Effort/Input (E)- The force a person uses when they use the lever Load/Output (L)- The force needed to move the object without a lever Fulcrum (F)- the pivot point (i.e. the elbow of an arm)
First-class lever: A first-class lever always has the fulcrum between the input and output forces.
Example of a first-class lever: A crowbar and a wooden box. The fulcrum in the crowbar is where the crowbar is touching the wooden box. The input force is the hand pushing down on the crowbar. The output force would be the tip of the crowbar, pushing the wooden box upward.
Why are there three classes?
There are three classes of levers because all are classified by the locations of the fulcrum, the input force, and the output force.
Key Terms:
Effort/Input (E)- The force a person uses when they use the lever
Load/Output (L)- The force needed to move the object without a lever
Fulcrum (F)- the pivot point (i.e. the elbow of an arm)
First-class lever:
A first-class lever always has the fulcrum between the input and output forces.
Example of a first-class lever: A crowbar and a wooden box.
The fulcrum in the crowbar is where the crowbar is touching the wooden box. The input force is the hand pushing down on the crowbar. The output force would be the tip of the crowbar, pushing the wooden box upward.