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Re: [Phys-l] differential equation solution request.



I'm still not clear on the damping term.
Regards,
Jack

On Mon, 13 Jul 2009, Bernard Cleyet wrote:

Jack is not the only person who, justifiably, complains. Perhaps
I'll have learned by the time I'm "totally" senile. I complain now,
as I made at least one error,*** which I likely wouldn't have if I'd
taken the trouble to write d(x)/dt, etc.

Back to the problem: I also shoulda left well enough alone w/ just:
(another notation-I think std.) X (double dot) + a*[X-dot]^2 *** +
b* X = 0 and the explanation -- It's an harmonic oscillator (not
driven) w/ non-linear dissipation.


*** I forgot my formula did not insure the "turbulent" damping was!
i.e. opposed to the direction). I think I got the coulomb damping
correctly.

D^2 + a*(D * |D|) + b*X = 0 or equivalently ...


This I much appreciate, as I was exporting the data to a different
app. that has the signum function -- I think the original has the
abs. function.

bc time wise, understanding foolish.

On 2009, Jul 13, , at 15:56, David Bowman wrote:

I agree that the notation is a bit ambiguous, but I suspect I
understood what BC was trying to say. I suppose I should have
rewritten my post using a better notation, but I thought, since I
was answering BC's question, he would best understand his own
notation.

David Bowman

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