[Phys-L] Re: pulse on a vertical rope

[herbs at WIDEOPENWEST.COM (Herb Schulz)]

On 12/29/04 3:57 PM, "Carl Mungan" <mungan@USNA.EDU> wrote:

> Going back over the derivation of the wave equation, it is not hard
> to show from Newton's second law that the wave equation is replaced by
>
> d^2y/dt^2 = gx*d^2y/dx^2 + g*dy/dx
>
> for small displacements in the transverse direction y.
>
> If the last term were not present, we would indeed say the wave speed
> is sqrt(gx).

Howdy,

I'm not sure this answers your question but... Folks usually make a ``small
amplitude approximation'' in which case won't dy/dx always be very small and
that term is neglegible?

Good Luck,

Herb Schulz
(herbs@wideopenwest.com)