Question

If a machine has an efficiency of 40%, and you do 1,000 J of work on the machine, what will be the work output of the machine?

Answer 1

400 J

Step-by-step explanation:

The efficiency of a machine is defined as

`\eta = (W_(out))/(W_(in))`

where

`W_(out)` is the work output

`W_(in)` is the work input

For this machine, we know the following

`W_(in) = 1000 J` is the work in input

`\eta = 40\% = 0.40` is the efficiency

Solving for the work output, we find

`W_(out) = \eta W_(in) = (0.40)(1000)=400 J`