Answer:
mechanical efficiency = 95 %
Explanation:
given data
work on cowbar = 500 J
work on nail = 475 J
solution
we get here mechanical efficiency of the crowbar that is express as
mechanical efficiency = [tex]\frac{work\ nail}{work\ cowbar}[/tex] × 100 .....................1
put here value we get
mechanical efficiency = [tex]\frac{475}{500}[/tex] × 100
mechanical efficiency = 0.95 × 100
mechanical efficiency = 95 %