From: Lee Corbin (lcorbin@tsoft.com)
Date: Wed Oct 16 2002 - 01:47:10 MDT
Spike writes
> Lee Corbin wrote:
> > Voila:
> >
> > 1 ft-lb = 1.355818 newtons.
>
> Oy Vey! A ft-lb is a force times a distance. A newton
> is a force.
Oh no! You're right! 1 ft-lb turns out to be
1.3558 joules, not newtons!
> See what a mess the English units cause us?
> It is Britain's revenge for that nasty
> General Washington affair back in 76.
I understand! I understand. Though, don't forget
that innocent British students are probably also
falling for the same traps I am.
> A newton is about a quarter of a pound, if
> you really really must know it in those terms.
> 2.2046/9.81 = 0.225 pounds force to the newton.
> About the weight of a stick of butter.
Okay, I'll try to stick with that!
> > Proof: 1kg weight (not mass) is equal to
> > 2.2046 pounds, as one knows from
> > daily life.
>
> Oy veeeeeyyyyyy! No Lee, no no my son, do not
> mess up the MKS system the way the English system
> is already messed up. Do not even utter the words
> 1 Kg weight. Baaad boy Lee! Bad!
But sir! I meant the force that a mass of 1kg
exerts in Earth's gravity.
> Kilograms are mass units only. ONLY!
Well, you will probably turn out to be right,
but I *want* to think about the force of a mass
of 1kg in Earth's gravity.
> The English system can be partially rehabilitated
> if one throws out the unit pound mass, and uses
> pound ONLY for force and slugs ONLY for mass.
Then I strive onwards (back to the drawing board
thanks to you!) to do the conversion without
reference to those ugly slugs!
> > So from now on I hope that it takes less than
> > hours to convert from ft-lbs (should the dreadful
> > need arise again) to newtons. Lee
>
> Did you mean ft-lbs to newton meters? A newton meter
> is a unit of work, also called a joule.
Yes; somehow my conversion technique resulted in
joules. I'm going back to study it again.
> A joule per second is a watt. Great system,
> very simple, elegant, none of those ugly horsepower
> units.
Yes, great.
> Speaking of which, a horsepower is 550 ft pounds
> per second. Whats up with that? That must have
> been one flimsy pony, with the flu, to only pull
> that much. Hell, a strong *human* can make almost
> that much power in a short burst. spike
Actually, I heard that it takes a kind of super-horse
to maintain 1 horsepower. And indeed, if you run up
a flight of stairs you're expending a *lot* of energy
per second---several horsepower IIRC.
Lee
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