Carlota does 2000 J of work on a machine. The machine does 500 J of work. What is the efficiency of the machine?

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%