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Re: [Phys-l] Final velocity of bullets



Hi:

It is true. I live in Hermosillo, Sonora, México and I read in the
newspaper, a few years ago, about someone who kill himself by shooting his
gun in a vertical direction. The bullet of his own gun hit his head.

Arnulfo Castellanos-Moreno




-----Mensaje original-----
De: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] En nombre de Roger Haar
Enviado el: Miércoles, 24 de Enero de 2007 08:52 a.m.
Para: Forum for Physics Educators
Asunto: Re: [Phys-l] Final velocity of bullets

Hi,

I am 99% sure that a few years ago in Phoenix, there was serious or
fatal injury from a celebratory near vertical gun shot. As I recall,
the bullet entered the top of the skull. Since then there has been a
media campaign to warn people not to do this and the police have
attempted to clamp down. Thus it is known experimentally that
vertically fired bullets can be deadly.

**********************************************************************
From Michael D. Edmiston, Ph.D.

(a) At what elevation must a typical gun be fired such that air friction
reduces the velocity sufficiently that the landing velocity is near
free-fall terminal velocity? I think we are agreed that a bullet fired
straight up will land at terminal velocity. I think we are also agreed
that a bullet fired at steep angle, but not straight up, will land with
some horizontal velocity in addition to terminal vertical velocity. Is
there an angle of launch above which a typical bullet is not lethal.
(And I think we realize this is gun and bullet dependent.)

**********************************************************************

I am no so sure that one can decompose air friction into components
like that. I think the horizontal velocity is going to effect the
vertical terminal velocity. The bullet/ air interaction is more
turbulent than viscous in nature so the drag force is proportional to
v^2 not v.

Thanks
Roger Haar


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