Re: [Phys-l] Killed by a Falling Bullet? - Myth busters.

[Brian Whatcott <betwys1@sbcglobal.net>]

At 07:11 PM 1/21/2007,  Jack, you wrote:

> The original post omitted a crucial step and seemed to encourage a lethal
> and dangerous practice.  A bullet fired upward at an engle that is not
> precisely vertical has horizontal as well as vertical velocity when it
> returns to earth - that's the principle of the howitzer, which is to lob
> artillery shells over obstacles.  Assuming that a bullet dropped from the
> maximum height of a vertically fired bullet is not lethal in all
> circumstance, what is the minimum deviation from exactly vertical that
> would make the bullet lethal in most circumstances.

///

>                                                         Jack

It may be helpful to pursue this point a little further.
I mentioned that a bullet may hit a live target with greater
than terminal velocity or at terminal velocity.
In the former case, it may well be lethal.
In the latter case it will give an unpleasant bruise, unless it hits
some vulnerable point. The one speed is higher than the other,
 of course.

For bullets of the usual calibers, there is no free fall at issue
 (except perhaps to high school teachers, for whom the vacuum
 approximation is helpful?)
But Jack's question is interesting, and in fact easily answered.
What is a plausible minimal angular offset from the vertical
that will  allow a given round to hit a target at  (much) greater
 than terminal velocity?   An iterative method answers this
 quickly - but I have no time until this evening.
One supposes there is a ground annulus that offers both
 possibilities.  If nobody cares to provide a concrete example
 I will work it after 8 tonight.

Sincerely

Brian Whatcott



Brian Whatcott    Altus OK    Eureka!