Mechanical Advantage, Velocity Ratio and Efficiency

Things to remember

• Mechanical advantage is defined as the ratio of resistance overcomes to the effort applied.
• Velocity ratio of simple machine is the ratio of distance travelled by effort to the distance travelled by load in the machine.
• The efficiency of a simple machine is defined as the ratio of useful work done by machine (output work) to the total work put into the machine (input work).
• For ideal or perfect machine, work output is equal to the work input but  in practice, the work output of a machine is always less than work input due to the effect of friction.