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Re: A Parents' Day gem



With regard to bullets fired horizontally:

The curvature of Earth is a fairly minor effect and I don't have too much
trouble accepting the proposition that we could idealize away the
assymetries of the bullet, its orientation with respect to its travel
direction, the possibility that the gun was not fired *exactly*
horizontally, or the possibility that the ground is not *exactly* level
all of which may result in significantly smaller or larger times in the
air.

You can't, however, ignore the effects of air resistance even on a
symmetrical bullet and, because its dependence on the velocity is greater
than linear, the fired bullet will receive more "lift" than the dropped
bullet. I just ran a couple of simulations and find that, for realistic
parameters, this effect can pretty easily cause a 10% larger flight time
for the bullet.

John

P.S. In my simulation, I assumed that gravity begins acting on the fired
bullet *immediately.* ;-)

P.P.S. No, I haven't done the experiment.
-----------------------------------------------------------------
A. John Mallinckrodt http://www.intranet.csupomona.edu/~ajm
Professor of Physics mailto:ajmallinckro@csupomona.edu
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Cal Poly Pomona fax:909-869-5090
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