Answer: Efficiency
Explanation:
The efficiency of a machine or actual Mechanical Advantage is measured by dividing the useful work output by the total work input.
The efficiency of a machine is the ratio of the work output to work input. The efficiency of a machine depends on the useful life of a machine because machines efficiency tends to reduce with time due to the amount of work done on it resulting in wear and tear of the moving parts because of the heat generated by friction.
