Find out the mechanical advantage of the machines:

A lifting machine may lift 800 N by the application of 100 N. Distance moved by the effort is 100 cm. At the same time load moves by 10 cm. find out the mechanical advantage, velocity ratio and efficiency of the machines.

Solution

Load lifted = 800 N Effort applied = 100 N

Distance moved by effort = 100 cm

Distance moved by load = 10 cm

Mechanical Advantage (M. A.) = W/ P = 800/100 = 8

Velocity Ration (V. R.) = y/ x = 100/10 = 10

Efficiency (n) = MA/ VR = 8/10

                                       = 0.8 or 80%

MA = 8, VR = 10 and η = 80% Ans.