Re: Explanation for Resonant Coupling?

[brian whatcott <inet@INTELLISYS.NET>]

Beware: handwaving explanation follows.
Phase and forced oscillation.

The suspending string starts exciting the still pendulum
at 180 deg phase difference. You would expect a phase difference
to persist. The phase difference ensures the energy taken to excite
the second pendulum subtracts from the first.
 The forcing energy offsets the natural frequencies so as to exhibit
 the beat frequency.
Brian


At 22:42 1/11/99 -0800, you wrote:
> Thanks for the explanation, but a couple of more questions...
>
> How do you explain the frequency with which the energy transfers from one
> pendulum to the other?
>
> Also, why can't both pendulums oscillate together so that their total
> energy would
> equal the inital energy?  Why does one slow down while the other picks up,
> and then after a certain period, the process reverses?
>
> On Mon, 11 Jan 1999, Homer B. James wrote:
>
> > Conservation of Energy.  Assuming a loss-less system, as the first pendulum
> > decreases the second must increase to maintain the same initial energy
> > (potential).
> >
> >
> >
> > At 03:33 PM 1/11/99 -0800, you wrote:
> > > I was wondering if someone could explain the following:
> > >
> > > Tie a string horizontally above the ground.  Tie two strings with small
> > > balls attached to them (pendulums) to the horizontal string.  Set one
> > > pendulum in motion.  Gradually it will come to a rest and the second
> > > pendulum will begin oscillating. ...
brian whatcott <inet@intellisys.net>
Altus OK