-=> Quoting Vern Humphrey to David R. Norton <=-
 DRN> GB> Are you familiar with the concept of 'terminal velocity' as applied
 DRN> GB> to objects falling in an atmosphere?
 DRN> I don't think a bullet will go high enough to fall far enough to reach
 DRN> terminal velocity, if it did the calculations would be real easy,
 DRN> wouldn't they!
 VH> It depends -- I've stood under a tree and had Number 6 shot rain down
 VH> through the leaves, where someone else had shot at a squirrel only
 VH> about a hundred yards away.  Those Number 6s had reached terminal
 VH> velocity rather quickly.
 How do you know the shot wouldn't have picked up a bit more speed if
 it had fallen farther?
 VH> A quick rule of thumb is this -- for equal shapes, drag increases with
 VH> the cross section (i.e., with the square) while momentum increases
 VH> with the mass -- which is directly proportionate to the volume (i.e.,
 VH> the cube.)
 VH> So if a given projectile has a known terminal velocity of, say 500
 VH> fps, a projectile of equal shape, but twice the diameter would have a
 VH> terminal velocity of 1,000 fps (the cube divided by the square, with
 VH> the diameter of the smaller projectile being 1.)
 VH> Let's say these Number 6s had a terminal velocity of 50 fps.  A
 VH> spherical projectile 10 with times the diameter of a Number 6 would
 VH> have a terminal velocity of about 500 fps.
 VH> Of course, when the terminal velocity is near or above the speed of
 VH> sound, this rule no longer holds.
 What I said, it's too complicated to figure with out taking off my
 shoes. 
 Take Care,
 David R. Norton [norton@doitnow.com]
... Hard work never killed anyone but why take the risk?
--- FMail 1.02
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