Question

How is the mechanical advantage related with the velocity ratio for an actual machine ? State whether the efficiency of such a machine is equal to 1, less than 1 or more than 1.

Answer 1

The mechanical advantage for an actual machine is equal to the product of its efficiency and velocity ratio


For a practical machine, the efficiency of such a machine is always less than 1, i.e. $h<1$. This is because there is always some loss of energy in form of friction etc.