Go to this website, it's great http://www.howstuffworks.com/horsepower.htm
Have fun with it!
Horsepower is a unit of work established by James Watt who lived until 1819. Watt wanted to measure the amount of energy required to raise coal out of a coal mine and so he created 'horsepower' as the unit of measure.
How much is one horsepower? One horsepower is equivalent to 33,000 foot-pounds of work performed in one minute. To give you a better sense of one horsepower, we have provided a list of equivalences - one horsepower equals all of the following:
lifting 33,000 pounds, 1 foot in one minute lifting 1 pound, 33,000 feet in one minute lifting 1000 pounds, 33 feet in one minute lifting 1000 pounds, 330 feet in ten minutes lifting 100 pounds, 33 feet in 6 seconds
