how is speed of sound affected in phases

[Oh_Gee]

this is what i think.
from highest to lowest
solid>liquid>air

speed of sound should also increase in denser materials of the same phase

does temperature affect this at all?

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[techfan]

As I understand it higher temperature means a higher KE which means a faster velocity.

 

[techfan]

This thread (http://forums.studentdoctor.net/threads/speed-of-sound.1022916/) had a good explanation:

Speed of sound depends on two properties of the medium. The inertial properties ("heaviness", or density of the particles of the medium) and elastic properties (stiffness, or how fast the particles snap back to their original positions).

A stiffer medium will have its molecules bounce around much more quickly because they want to snap back to position right away, transmitting the sound wave faster through it. See thisanimation.

A "lighter" medium will also have its particles bouncing more quickly to transmit the sound wave. Think of making a wave with a length of hose vs a cotton string. It's much easier to get a wave going in a lighter material, which is less resistant to changing its motion.

Gases are less elastic vs solids and liquids because the molecules are so far apart, so they transmit waves more slowly compared to solids and liquids.

However, if you compare gases to other gases, some transmit sound more quickly than others. This is due to the inertial property that affects sound transmission. The "lighter" (less dense) gas particles will bounce around more easily, transmitting the sound wave faster.

 

[Oh_Gee]

This thread (http://forums.studentdoctor.net/threads/speed-of-sound.1022916/) had a good explanation:

Speed of sound depends on two properties of the medium. The inertial properties ("heaviness", or density of the particles of the medium) and elastic properties (stiffness, or how fast the particles snap back to their original positions).

A stiffer medium will have its molecules bounce around much more quickly because they want to snap back to position right away, transmitting the sound wave faster through it. See thisanimation.

A "lighter" medium will also have its particles bouncing more quickly to transmit the sound wave. Think of making a wave with a length of hose vs a cotton string. It's much easier to get a wave going in a lighter material, which is less resistant to changing its motion.

Gases are less elastic vs solids and liquids because the molecules are so far apart, so they transmit waves more slowly compared to solids and liquids.

However, if you compare gases to other gases, some transmit sound more quickly than others. This is due to the inertial property that affects sound transmission. The "lighter" (less dense) gas particles will bounce around more easily, transmitting the sound wave faster.

so sound will travel faster or slower at high altitudes where there's low temperatures but less dense gas? a double whammy

 

[techfan]

Well from TBR the equation is v=sqrt(gamma*RT/M)=sqrt(gamma*P/rho).

gamma=Cp/Cv
rho=density
M=molecular mass
P=pressure
R=gas constant
T=Temperature

So if you lower temperature AND lower density they both act in the same direction so you'd just have to see which one is greater.

 

[Oh_Gee]

Well from TBR the equation is v=sqrt(gamma*RT/M)=sqrt(gamma*P/rho).

gamma=Cp/Cv
rho=density
M=molecular mass
P=pressure
R=gas constant
T=Temperature

So if you lower temperature AND lower density they both act in the same direction so you'd just have to see which one is greater.

what page of TBR

 

[techfan]

I don't have it on me, but it was in Physics Part 2 in the first section (I think section 6 overall) on sound.