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)
Third-class levers: The third-class lever has an effort force between the fulcrum and the load force, and the effort and load force are in the same direction.
Why the mechanical advantage is always less than 1: In third-class levers the mechanical advantage is always less than 1 because the load arm is always longer than the effort arm. In the formula it's MA= effort divided by load which makes it less than one.
Example of a third-class lever: tweezers The fulcrum in the tweezers would be the end point of the tweezers. The effort force is the middle of the tweezers. The load force is the separated part.
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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)
Third-class levers:
The third-class lever has an effort force between the fulcrum and the load force, and the effort and load force are in the same direction.
Why the mechanical advantage is always less than 1:
In third-class levers the mechanical advantage is always less than 1 because the load arm is always longer than the effort arm. In the formula it's MA= effort divided by load which makes it less than one.
Example of a third-class lever: tweezers
The fulcrum in the tweezers would be the end point of the tweezers. The effort force is the middle of the tweezers. The load force is the separated part.