Re: Re: Weapon Selection
By: Mouse to Angus Mcleod on Wed Jul 02 2003 19:51:00

MV + mv = (M+m)v'

M = mass of man
V = velcoity of the man
m = mass of bullet
v = velocity of the bullet

v' = velocity of the inelasticly collided masses after the event.

If any energy if lost to deformation, sound, shockwaves, light, whatever, th energy cannot be used to move the target. In the case of a bullet, a huge percentage the systems energy is lost to inelastic effects. But the momentu after the collison stays the same by conservation of momentum. Conservation energy holds, but MECHANICAL energy, the important stuff in this case, does not.

Interesting and thought-provoking.

To grant you a fact, though, deformation (bones breaking, bullet shattering, shockwave effects) have a huge effect on the dropping power of the firearm. Pushing someone back is a function of momentum, however. Take it from the s to be Physics graduate and teacher....

Accepted. However, I still take issue with Hatcherites. Agreed, the best exit velocity is zero? Then the total energy of the bullet is mv^2 at time of impact and all this energy is available for deformation, as you so delicately describe it! :) Similarly, if it is important to you to displace the assailant, and given that your values M and V are fixed the scenario, then the only thing you have control over are m and v. Doubling v has the same effect as doubling m when it comes to momentum, but in pure energy terms, doubling v has _twice_ the effect of doubling m! So given some base values of m and v from which you are contemplating an upgrade, you are better off (IMHO) with an increase in v rather than a comparable increase in m. Increasing v proportionately increases your momentum, and _greatly_ increases your deformation, particularly if you can achieve sufficiently high levels of v that bring hydrostatic shock into play.

The one caveat is that you MUST have a good choice of bullet here. There is no point increasing the velicity to the point where you drill neat holes and the departure velocity od 97% of impact! You have to have a reliably frangible bullet. And thank goodness the Geneva Conventions don't apply to us!

BTW, I hear there is a solid-copper slug that meets the Geneva Convention's rules about non-frangible bullets. There being no lead, the velocity is _very_ high, with tremendous dammage being done via hydrostatic shock. Have never seen these rounds. Any knowledge of them on your end?

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