🚀 go-pugleaf

On Sat, 6 May 1995, Donald E. Simanek wrote:

> On Sat, 6 May 1995, Mervin Koehlinger wrote:
>
> > On Fri, 5 May 1995, David J. Abineri wrote:
> >
> > > Look at a standing wave on a slinky. The nodal points are stationary. How
>  does
> > > the disturbance get from one side of a nodal point to the other if that
>  point
> > > isn't able to move?  It would seem that any disturbance would be stopped
>  when
> > > it reaches a node.
> > >
> > > If two congruent pulses are sent on Opposite sides of the spring
> > > simultaneously they cancel exactly at one moment in time. Is there any way
>  to
> > > know whether, after that instant, the waves continue in the same direction
> > > they were moving or in fact "bounce" off each other and return to their
> > > respective starting ends.
> > >
> > > Any help on these would be appreciated. Thanks.  David Abineri
> > >
> > The motion of any particle in a translational wave is "forced" by the one
> > next to it.  In a standing wave, two waves are traveling in opposite
> > directions.  Thus a particle is being "forced" by two particles, one on
> > either side of it.  The particle at the node experiences equal and
> > opposite forces from the particles on either side of it.  Hence, it
> > doesn't move.
> >
> > The node would be a fixed end termination.  Hence, the wave is actually
> > reflected at the node.  It does not travel through.
>
> For the higher harmonics there are nodes between the ends of the spring,
> so this answer doesn't David's concern.
>
>         -- Donald
>
I should have phrased my answer differently: Since the nodes are held in
position by the opposing forces, they "act like" like fixed end terminations.

Mervin Koehlinger