Physics Professors...I'm confused about Kinetic Energy Numbers?

[7tenz]

KE = (bullet weight in grains) x (velocity in fps)^2 /(constant)

and the constant is 2 x 7000 x 32.2 = 450,800

Try it, for a 158 gr bullet at 850 fps. First, enter 850, then square it. Then multiply by 158. Then divide by 450800. Out pops 253 ft-lb.

So it looks like this:
(pounds x feet squared x seconds squared)/(feet x seconds squared)


This would have been a whole lot easier both to explain and understand with a piece of paper and a pencil. Or a blackboard.

I sit corrected. I forgot where the constant came from, but I saw it expanded in of all places a Lyman reloading manual many years ago. Thanks for the info. It's hard to fathom. Even Newton didn't get it completely. I always did it like e=(V^2/C)M. Same thing, only different

 

[smith revolver cop]

Whoa whoa.. let me stop you right there.

EVERYONE knows that .45 acp has the most stopping power. They load more stopping power powder into the casing and the bullet itself is soooo big you can throw it at someone and it'll stop them.

.45 acp = stopping power




(by the way, this is essentially how some "stopping power" conversation go on other forums)

Are those the same forums where 50% of the posts are about how the 1911 is the "only" gun, and the other 50% of the posts detail all of the extra things you need to do to your 1911 to make it shoot right???!!!