Linear transmission of motion - Levers

A lever is a rigidbar that turns around a point called a fulcrum. Various forces may act on the lever at the same time.

Each force produces a specific torque, which is the force multiplied by its distance from the fulcrum.

                                               Torque = Force x Distance
                                                   
                                                           F x d = R x r
                                            
Classes of levers 
We can divide levers into classes according to the locations of the fulcrum, force and resistance.