Efficiency of a Lifting Machine:

Efficiency of a machine is explained as the ratio of the output of the machine to the input of the machine.

 Input of machine        = work done on the machine

                                      = effort × distance moved by the effort

                                      = P × y

Output of a machine = work done by the machine

                                   = load × distance moved by load

                                    = W × x

Thus efficiency of machine

η = (W × x )/ (P × y )=   ( W/P)/( y/x)  = MA/ VR