Re: A Parents' Day gem

[Maurice Barnhill <mvb@UDel.Edu>]

Leigh Palmer wrote:
> (I thought John Mallinckrodt's observation about a retarding force
> having a greater than first power velocity dependence providing
> effective lift to be a revelation here. I'd never heard of such a
> thing, but it is obviously true - and significant. It explains for
> me why bullets fired from a rifle don't fall with acceleration g.
> I have written an authority for information on this topic and I
> will, of course, share it when I get it.)

I am very much looking forward to this information.  The notion of the
retarding force being proportional to v-squared is an approximation, and
I have seen that approximation used only for calculating the force
opposite to the direction of motion.  I wonder if the lift effect is a
reflection of the data or only a case of a limited model being applied
outside of its range of validity.
-- 
Maurice Barnhill, mvb@udel.edu                
http://www.physics.udel.edu/~barnhill/          
Physics Dept., University of Delaware, Newark, DE 19716