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

Answer:

400 J

Explanation:

The efficiency of a machine is defined as

$\eta = \frac{W_{out}}{W_{in}}$

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

$W_{out} = \eta W_{in} = (0.40)(1000)=400 J$