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Re: [Phys-l] Final velocity of bullets



My spreadsheet calculations (described earlier) included air-resistance in both the vertical and horizontal directions. What one finds is that as the angle increases and the time of flight increases the horizontal component tends to get quite small. This then leads to the fact that the final speed (properly derived from the horizontal and vertical velocities) tends not to vary too much--for my model no more than by 4m/s over 5-90 degree launches. However, dropping to 1 degree did increase the final speed by over a factor of two and if fired horizontally from 2 meters up, the short flight time would guarantee a final speed much nearer the muzzle velocity.

Rick


I don't agree with Michael's paragraph above and I suspect it
illustrates a difficulty that Rick also hinted at with his model.
Here are the fatal words:
" [it] will land with some horizontal velocity in addition to
terminal vertical velocity".

While it is insightful to point out the separation of horizontal
and vertical motion for assigning gravity mediated
acceleration, it is an error to suppose that terminal velocity
is something that affects only the vertical component of velocity.

Air drag in fact opposes the instantaneous direction of flight as a
generalization I therefore hope that the sentiment was just a locution
rather than a carried over concept.


Brian Whatcott Altus OK Eureka!