Answer:
400 J
Explanation:
The efficiency of a machine is defined as
[tex]\eta = \frac{W_{out}}{W_{in}}[/tex]
where
[tex]W_{out}[/tex] is the work output
[tex]W_{in}[/tex] is the work input
For this machine, we know the following
[tex]W_{in} = 1000 J[/tex] is the work in input
[tex]\eta = 40\% = 0.40[/tex] is the efficiency
Solving for the work output, we find
[tex]W_{out} = \eta W_{in} = (0.40)(1000)=400 J[/tex]
