Anybody remember PLANK from an introductory Physics class?
"Also asserting that 1 HP is somehow not equal to 746 watts is like
saying that 1 inch does not "have" to equal 2.54 cm. A gallon of
water is still the same amount no matter what units you choose (or
what container you put it in.)"
Horsepower depends upon whom you are talking to:
Then there is the imperial gallon:
Even the centimeter has changed over time.
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