The work done by a boy pulling a snow sled up a hill is 425 J. What is the power expended by the boy if he pulls on the sled for 10.5 s?
However, in more simple applications, you can just write this as:
You're given work, and you're given time, so we just plug in & solve:
Note that 1 watt = 1 Joule per second.
Hope that helped :)