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

[Bernard Cleyet <bernardcleyet@redshift.com>]

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