Question

You input 75 J of work with a wedge. If the wedge does 65 J of useful work, what if the efficiency of the wedge ?

Answer 1

Efficiency of wedge is the ratio of "work done by the machine to the work supplied to the machine".

Efficiency (η) = Work done by machine ÷ Work supplied

= 65 ÷ 75

= 0.86%

Efficiency of wedge is 86%