Although you've already posted a definition of 'horse power,' how can I more easily visualize what it means? Example, an engine has 100 horse power; can I equate that with 100 horses straining to pull a heavy object a certain distance at a certain velocity?

Asked by: Greg Armbruster

Answer

One horsepower provides the ability to do 550 ft-lbs of work every second. 550 ft-lbs of work is any product of force (in pounds) and distance (in feet) equaling that number.

Applying 55 lbs of force through a distance of 10 feet, for example, represents the same amount of work as 11 lbs. of force applied through 50 feet. The force can be used to lift objects against the pull of gravity, drag them along the ground against frictional forces, accelerate objects, etc.

A 100 HP motor would let you do 550 X 100 or 55,000 ft-lbs. of work each second. It could, for example, lift 550 lbs. 100 feet in one second. To lift more weight at the same rate, or the same weight more quickly, you would need more horsepower.
Answered by: Paul Walorski, B.A. Physics, Part-time Physics Instructor