Class 3 Lever

The figure shown here illustrates the key components of a Class 3 Lever. There is no change in the definitions of F1, F2, L1 and L2. Therefore, as far as calculations are concerned, there is no difference in application of F1, F2, L1 and L2. BUT there is a big difference in the functionality of this class. In this case we use a bigger force to lift a smaller force. Here are its main components:

F1: This is the force (effort) we apply. But this force is applied at point located between the fulcrum and F2.

F2: The application of force F1 results in generation of force (F2). F2 is located at one end of the lever. The fulcrum is located at the other end.

L1: This is the distance between the applied force and the fulcrum.

L2: This is the distance between the point where the weight acts and the fulcrum.