🚀 go-pugleaf

On Fri, 5 May 1995, David J. Abineri wrote:

> Another high school physics question that I had a hard time answering.
>
> 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.
>
> Also, if two transverse pulses (congruent) are sent from bot ends on the same
>         Sorry - start again
>
> 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.

Mervin Koehlinger
Parkway HS
Rockford, OH