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Re: Problem



At 15:12 -0400 9/18/01, Bob Sciamanda wrote:

Hugh, the square of the speed is given by

V(t)^2 = (Vo*CosTH)^2 +(Vo*SinTH-gt)^2

The time derivative of this goes through zero at the top of the
trajectory,
ie: at t = (Vo*SinTH)/g

I think not, Bob. If you take the derivative of V(t) (the square root
of your espression above), I think that you will find that it equals
-g, which it should, since this is in a uniform grav. field, by the
statement of the problem.

Furthermore, take the special case when TH=90 degrees, i.e., a
vertical trajectory. Are you telling me that when the object gets to
the very top it's acceleration goes to zero? IF so, how does it get
back down?

Hugh
--

Hugh Haskell
<mailto://haskell@ncssm.edu>
<mailto://hhaskell@mindspring.com>

(919) 467-7610

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