Horse Power

Horse Power

Horsepower is usually calculated in the English system, (not necessarily in the world-wide metric system used in science and technology).

Before calculating horsepower, (HP); Work (W) must be found first.  And W = Force x Distance, where force is measured in pounds, distance is measured in feet, and Work is measured in foot pounds.

The next step is to divide the Work by the Time; W/T = Power, where the quicker the work is done, the greater the power value will be. The label is in ft.lbs per second. Or ft.lbs/sec

One HP is equal to 550 ft.lbs per second, or 550 ft.lbs/sec. So, after calculating Power, a division by 550 ft.lbs./sec, will give the Horsepower or HP. The labels cancel out, and HP has no label other than it's value.

Example: A machine that moves 110 pounds, a distance of 20 feet produces 2200 ft.lbs. of Work. If the machine can do this task in 2 seconds, then the Power of the machine is 1100 ft.lbs.per second. Divide the Power by 550 ft.lbs.per second, and the HP for the machine is 2.