Answer:
25%
Explanation:
Efficiency of a machine: This can be defined as the ratio of work output to work input of a machine, expressed in percentage. mathematically, it can be represented as
E(%) = (work output/work input)×100/1................................... Equation 1
Given: Work output = 500 J, Work input = 2000 J
Substituting into equation 1
E(%) = (500/2000)×100
E(%) = 25%
Hence the efficiency of the machine is 25%
