Re: Speed of Waves

[Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>]

Let me say it a little better. Average (rms)  speeds of molecules
can be theoretically calculated at room temperature (for example).
Suppose we plot them along the x axis, for several gases (from
as light as H2 to as heavy as UF4) while the corresponding
speeds of sound (experimental, from a table) are plotted along
the y axis. A strong correlation does not prove anything but it
can be very indicative. Absence of correlation can be even more
significant, I think. I have no idea if the bulk modulus of a gas
is correlated with the rms speed of its molecules.

Ludwik Kowalski wrote:

> I do not know how to answer this question, Leigh. But here
> is what I would do if had data on speeds of sound in different
> gasses. Since the speed of molecules is inversely proportional
> to 1/sqr(M), where M is the molecular mass, I would plot
> known speeds of sound, at a given T, versus 1/sqr(M).
> Ludic
>
> Leigh Palmer wrote:
>
> > One question I've asked before has never been answered well enough so
> > that I internalized the answer. I'll try it again:
> >
> > The speed of sound in a gas is the same as the speed of the molecules
> > in the gas, more or less. Why should this be? The propagation of sound
> > is not a phenomenon which depends upon the microscopic structure of
> > the medium. Is this just a fluke, or is there a deeper connection?