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Re: AW: Underwater latency (not completely OT) ;-)

Thanks Doug.  Sounds as if I'm misremembering some of my class notes.

I'll go through and work some sample equations to confirm.  However, 
there's one quoted passage that just reads wrong to me: "The denser and 
lower the compressibility, the slower the sound waves would travel. 
Therefore, the speed of sound is about four times faster in water than in 

Does that read weird to anybody else (like he's contradicting himself), or 
is it just me...?


At 03:17 PM 3/15/2005, Doug Cox wrote:
>This can be found here: http://hypertextbook.com/facts/2000/NickyDu.shtml
>Sound is a type of longitudinal, mechanical wave. They need a medium to 
>propagate and will not travel through a vacuum. Sound travels at 
>speed in different media. The speed of sound is determined by the density 
>and compressibility of the medium. Density is the amount of material in a 
>given volume, and compressibility is the how compacted could a substance 
>become for a given pressure. The denser and the lower the 
>the slower the sound waves would travel. Therefore, the speed of sound is 
>about four times faster in water than in air. The speed of sound can also 
>be affected by temperature. Sound waves tend to travel faster at higher 
>temperatures. I have found different values for the speed of sound in 
>water in different sources. They range from 1450 to 1498 meters per 
>(m/s) in distilled water and 1531 m/s in sea water at room temperatures 
>(20 to 25 °C).
>The speed of sound in a medium can be determined by the equation...
>/v/ = (/B//ρ)^1/2
>    /v/ is the speed of sound,
>    /B/ is the bulk modulus of elasticity, and
>    ρ (rho) is the density.
>The bulk modulus of elasticity, also known as the compressibility, is the 
>relationship between pressure and volume. It is a measure of how much an 
>increase in pressure would decrease the volume.
>Nicky Du -- 2000
>Jesse Lucas wrote:
>>Rainer Thelonius Balthasar Straschill wrote:
>>>If I remember my (very) basic university classes in physics, we usually
>>>would test any theories we might have by bringing them to extreme values
>>>and see what happens. If lower density = lower speed of sound, then we
>>>would have sound travelling at infinite speed in vacuum. I don't believe
>>>this is the case.
>>In space there is no medium for sound to travel through. See the tag 
>>to the film "Alien."