Trust me!Originally posted by robinghewitt
I think not
Furthermore, the imperial measure of mass is 'slugs' not pounds (which is really a measure of weight/force).
Trust me!Originally posted by robinghewitt
I think not
Furthermore, the imperial measure of mass is 'slugs' not pounds (which is really a measure of weight/force).
Last edited by Numb Nut; 08-04-2004 at 05:04 PM.
Originally posted by robinghewitt
Works in Imperial just the same
Energy = foot poundals
Mass = pounds
Velocity = fps
It only gets silly if you insist on using bizarre units like foot pounds and grains
The beauty of the metric system is that it allows you to compare different forms of energy.
How many fpe is there in a portion of cereals?
How many fpe does a 60W bulb burn in an hour?
How many fpe do I produce during a training ride on my bicycle?
Et.c.......
I think notFurthermore, the imperial measure of mass is 'slugs' not pounds (which is really a measure of weight/force).
Rustram had better stop reading at this point A poundal is the force that will accelerate a mass of 1 pound at 1 ft/s/s
If you drop a mass of 1 lb it will accelerate at 32.16 ft/s/s so it is obviously being accelerated by a force of 32.16 poundals. That is where gravity appears to come into the equasion but doesn't really.
It's people who insist on using lbf for ballistics who muddle it all up. A slug is the mass that will accelerate at 1 ft/s/s when acted on by a force of 1 lbf. A ghastly fudge to make the maths work. This is why we divide by 450240, that's 225120 to convert grains to slugs and the half bit of 1/2 mv2
In metric, Joules = Newton metres. If you started using kgf instead of Newtons it would booger that up as well.
Robin, I've looked up what a poundal is and have found that it is a unit of force, where 1 poundal = 32.17 pounds. Thus 1 foot poundal = 32.17 foot pounds.
This means that both our equations are equivalent, yours gives the measure of kinetic energy in foot poundals and mine gives the result in foot pounds. Sorted!