Question

What is the power of a machine that pushes with a force of 3 n for a distance of 9 m in 8 s?

Answer 1

The work done by the machine is equal to the product between the force applied and the distance over which the force is applieds, so in this case:
$W=Fd=(3 N)(9 m)=27 J$

And the power of the machine is equal to the ratio between the work done by the machine and the time taken:
$P= \frac{W}{t}= \frac{27 J}{8 s}=3.38 W$