MECHANICAL EFFICIENCY
In Physics, the term mechanical efficiency refers to the efficiency of a real system and its contrast with an ideal system. It is the ratio of of actual work output to ideal work output. Since the second law of thermodynamics states that the quality of energy will decay through the production of entropy, one should understand that a real system will always be less than 100% efficient. Thus,
Mechanical Efficiency = (Work Output)/(Ideal Work Output)