Answer:
50%
Explanation:
Given parameters:
Work output = 30J
Work input = 60J
Unknown:
Efficiency of the lever = ?
Solution:
To solve this problem, the efficiency is taken as the ratio of the work output to that of the work input;
Efficiency = Work output / Work input x 100
Efficiency = [tex]\frac{30}{60}[/tex] x 100 = 50%
