Force Transformers

The law of conservation of energy says that energy can neither be created nor destroyed. We can, however, change one form of energy into another. We can also conclude that work done by a device can never exceed the input energy.

Force, however, is a different matter. By using some mechanical devices we are able to transform forces in a manner which is beneficial to us. But, remember, the work done by the force, no matter how it is transformed, must obey the energy law.

Levers

A lever is a simple force transformer. The figure provided here illustrates the components of a simple lever.

The simplest form of a lever is a rod or a beam as shown by the brown horizontal plank in the figure. For our discussion purposes we are assuming that this beam is sturdy (doesn't bend) and weightless. It can pivot around a fulcrum, which is located below the beam. The right hand side of the beam rests on a supporting structure. A 50 lb weight is placed on the right hand side of the lever.