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Smitty Two wrote:
> In article <6lTUe.933$LS5.383@newsread3.news.pas.earthlink.net>,
> Dave S <Dastaten@earthlink.net> wrote:
>
> > Smitty Two wrote:
> >
> > > 1. I didn't stipulate a vacuum. My engine and wing do not work very well
> > > without air. I said, to simplify calculations, ignore the effects of
> > > friction on the projectile. We are flying above the earth.
> >
> > You said discounting air friction. This is key to the problem. No air
> > friction would be the physical equivalent of being in a vacuum.
> >
> > If there were no air friction, the projectile would continue ahead with
> > a forward speed of 1500 mph - its own 500 mph from its spent propellant
> > charge, and the 1000 mph imparted to it from the airframe.
> >
> ...
> >
> > So... are we or are we not including air friction? If we are, I'm not
> > going to hazard a guess.. my math gland atrophied long ago after I
> > passed calculus. If we are not, then the problem is unsolvable in level
> > flight on earth.
> >
Neglecting airfriction, the trajectory relative to the aircraft,
of the bullets fired from that aricraft will be the same
as the trajectory of bullets fired from a fixed position,
relative to that fixed position. As OP noted, the gunner hits
his own aircraft by firing staight up.
No Calculus required to reach that conclusion.
>
> It's a hypothetical question, of course. I think I stated it fairly
> clearly. Bill has already answered it correctly, with a second from
> Alex. My calculus skills have also eroded over the years, which is one
> reason I wanted to discount friction. But, I would be curious to learn what
> the real world answer would be, including friction, which of course is
> dependent on a whole host of factors. (Of course, by the time the plane
> caught up with the bullet in the real world, the friction would likely
> have reduced its speed to something *relatively* harmless.)
That all depends on the relative velocity. If he fires upward and
forward and then does a low yo-yo to intercept I expect the bullets
could come down hard enough to hurt.
--
FF
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Re: shooting yourself down - more physics?
