The derivation of horsepower

Horse power
The term horsepower was coined in the late 18th century when James Watts was looking for a way to convince brewery owners to replace horses with steam engines.

Ever wonder where the term “horsepower” came from? The term was coined in the end of the 18th century by Scottish Engineer James Watt, who needed a way to compare his newly improved steam engines to the traditional horse wheel used in breweries. He saw breweries as ideal customers for steam engines because the process required so much energy.

A brewery horse was attached to the mill that ground the mash for making beer. It walked in a continuous circle of 24 feet in diameter, pulling with a force of 180 pounds and traveling at a speed of 180.96 feet per minute.

Watt determined that a strong horse could lift 150 pounds of water 220 feet in one minute. Therefore one horsepower is equal to 150 x220/1 or 33,000 foot pounds per minute or 745.699872 watts.

The term horsepower was later applied to early cars because the horseless carriage was compared to the horse-drawn carriage.

Today, the average compact car has 130-150 hp; a mid-size car has 160-180 hp; and a luxury car has 265-330 hp.

Me, I’m pretty amazed how much power there is in one horse.

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