Class 3 Lever - continued

A Class 3 Lever is characterized by:

a. L2 is greater than L1

b. F1 is greater than F2.

c. MA is less than 1 (that means we can use a large force to lift a lighter weight).

d. F1 and F2 act in the same direction.

e. F1 is located between F2 and the fulcrum.

At the lower part of the illustration, all of the necessary formulas are provided. Notice that they are identical to what was shown for the class 1 lever.

Now the obvious question is why we would want to use a greater force to lift a smaller weight. What is the advantage in doing so?

The advantage lies in the application of such an arrangement. Human arm is configured as a Class 3 lever.