Speed of a sound wave

[Primarygun]

Which of the sound wave travels at a higher speed?

In air, In carbon dioxide.

[Ophiolite]

What is the air pressure? What is the carbon dioxide pressure? Is that enough of a hint?

[YT2095]

Yup, it`s all about Density, the more Dense a material (gas in this instance) the faster sound waves will propagate

[Primarygun]

I don't know. Someone told me that it travels faster in air.

[Asimov Pupil]

density,density,density it's the same as steel and helium!

[Mokele]

Speed of sound = (gamma*R*T)^1/2

 

Where T is temp, R is the ideal gas constant, and gamma is a property of the material, the nature of which I've completely forgotten. You look it up in tables in the back of the book.

 

Pressure and density are involved because P= (density)*RT, and that can be re-arranged and substituted into the equation.

 

Mokele

[The Thing]

Sound waves are transverse waves, which means that they, unlike electromagnetic waves, require the movements of particles to carry it across. It is the compression of particles and the de-compression of them. Now, as we all know, in solids, or in denser materials, the particles are more packed, which means that they will compress and de-compress easier cuz they are right beside each other, and thus carry the transverse wave across faster. And in low density gases the particles are far apart, thus making the wave travel slower. Sound travels in, say, steel many times faster than it does in the air. (think how people putting a stick in their teeth and the other end on the railroad to test to see if any train is apporaching).

[Primarygun]

Sound waves are transverse waves

Sound waves are longitudinal waves.

[Janus]

As stated above, the speed of sound in a gas is:

[math]v= \sqrt{\gamma R T}[/math]

 

Gamma is the Ratio of specific heats

R in the gas constant

T is the Temp in Kelvin.

 

For air:

Gamma = 1.4

R = 286

 

For CO2:

 

Gamma = 1.3

R= 189

 

From this it is obvious that sound travels faster in air. (330 m/s vs 259 m/s at 0 degrees C)

[Primarygun]

Thank you very much.

For air:

Gamma = 1.4

R = 286

 

For CO2:

 

Gamma = 1.3

R= 189

What is a probable reason for this observation? Sound wave travel slower in CO2 than air only? How about other gases, such as Hydrogen?