I said "bubbly" mixture. There's a world of difference between that
and an aerosol. The speed of sound is proportional to the square
root of the coefficient of elasticity of the mixture to it's
density. The addition of bubbles greatly reduces thia coefficient
while having a small effect on the density. The speed of sound
plunges. In the 60s I had a PhD student at Princeton study the flow
of bubbly mixtures in a convergent-divergent nozzle. Shock waves in
the divergent portion of the nozzle were readily obtained at low
speeds and agreed very well with conventional one-d supersonic flow
theory.
This is getting pretty far off topic!
Roger
On 5 Dec 2007, at 12:01 PM, karl shah-jenner wrote:
Roger writes:
: Not to contradict any thing you say, but the speed of sound in
bubbly
: mixture (which one will have in a soda when the pressure is
released)
: is very low. -- of the order of feet per second.
there's still connecting liquid - if it were a dispersed aerosol
then yes, it would be slower than solid fluid, but it's
considerably faster in liquid than in air , and the more moisture
in the air, the faster sound travels for example in dry air the
speed is roughly 331m/s, in fog it approaches 402m/s (even though
the sound is dispersed)
Also, the speed of sound increases in air with increased
temperature too, from 346m/s at 25C to 365m/s at 60C
comparison - speed of sound in dry air at 30C is around 331m/s
muzzel velocity of a .303 is around 780m/s
the speed of sound in water is around 1497 m/s
karl
