A machine has an efficiency of 80%. How much work must be done on the machine so to make it do 50,000 J of output work?

Work formula is Work=N∙M or Joule (J)

So you have the following given:

50 000 is the output work

.8 is the efficiency

if you input the given = 50000 =.8*J

To get the answer just divide 50000 by. 8 to get the answer.

62,500 J is the amount of work to be done.