Derive a relationship between mechanical advantage, velocity ratio and efficiency of a machine.
Let a machine overcome a load L by the application of an effort E.
In time t, let the displacement of effort be dE and the displacement of the load be dL.
Work input = Effort × displacement of effort
= E × dE
Work output = Load × Displacement of load
= L × dL
But,
=
M.A. = V.R. ×
Thus, the mechanical advantage of a machine is equal to the product of its efficiency and velocity ratio