Re: [DMCForum] ATTN: Jim Strickland -- "300 HP" Does *NOT* Mean "300Hors
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Re: [DMCForum] ATTN: Jim Strickland -- "300 HP" Does *NOT* Mean "300Horses Coupled Together"
- From: Martin Gutkowski <webmaster@xxxxxxxxxxxxxx>
- Date: Tue, 13 Jan 2004 21:33:39 +0000
>You've got the equation a bit backwards: HP = Torque x RPM /5252. I'm
>not making "$hit" up -- that's how HP is calculated.
Only if you measure torque in ft-lbs. The correct statement is that HP
is a product of torque and speed. The fact that you also multiply by an
arbitary constant makes no difference as it's unitless. Which brings me
onto my next bit...
>HP is basically a measure of TIME,
Utter utter utter bollocks. HP is a unit of power and is (from memory)
equal to 768W. A watt is 1 joule of energy transferred in one second.
Again from memory, it's the energy required (in a 100% efficient system)
to lift a mass of 1kg to a height of 1m at sea level (gravity =
9.81m/s^2 meaning a force of 9.81Newtons is acting in the opposite
direction). If you do it in 1 second, you've made your 1 watt. Lift it
in half a second, and it'll take 2W of power to do it. You can do it
over 2 seconds and the power required is half a watt. Get where I'm
going with this? Power is directly proportional to speed and in this
case, we're keeping the force Torque is rotational force, measured in
terms of newton metres - ie 1Nm is the rotation induced by a metre long
stick with a 1N weight on the end.
I dont know what age you guys did this basic physics at school, but I
did it at 14-16.
>seen vehicles with low torque engines struggle to reach the top of a
>long steep grade with NOTHING coupled to their rear.
OK, and what did your driving instructor tell you to do in dire
circumstances like this? Turn around and do it in Reverse as it's the
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