Question

A man pushes down on a lever with 45 N and the lever moves 1.5 meters. The other end of the lever lifts a 87.6 N box .4 meters. What is the efficiency of the lever?

Answer 1

The input work = Force x distance
So I/P = 45 x 1.5 = 67.5 N.m

The output work = Force x distance
So, O/P = 87.6 x 0.4 = 35.04 N.m

Efficiency = (output work / Inputwork) x 100
= ( 35.04/67.5) x100

Efficiency = 51.91 %