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Old 06-06-2014, 11:01 AM   #82
Raven604
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Quote:
Originally Posted by Luckrider View Post
Horsepower is a rate of work. It is literally define in watts and I remember when I was taking physics in highschool that is was an semi-arbitrary amount chosen as common rate of work that a horse was able to accomplish, if I remember correctly, somewhere about 734 Watts. A Watt is defined in Joules/seconds. A Joule is an amount of work and seconds are a length of time. This means a Watt is defined a work/time.

Now lets think about horsepower. HP is rated in (torque*RPM)/5250. RPMs are a speed with a defined time. In reality, 5250 is 1 minute. Thinking about the units we are applying helps show us their origin. As you can see here, we are getting work/time again. It simply becomes a multiplication factor as we are able to continue doing the same amount of work in less time (which is what revving over 5250 means). I could get into the conversions and how 5250 really came to be, but in all reality, I have neither the desire or dedication to dig up that math and try to write it out in a forum post.
746w...and 5252

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