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cobrastrike
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Speed of sound!
Why does sound travel faster through warm air then cold air?
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Why does sound travel faster through warm air then cold air?
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cobrastrike said:Why does sound travel faster through warm air then cold air?
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jarednjames said:For every 1 degree celsius the temperature increases, the speed of sound increases by 0.6m/s.
nasu said:The speed of sound decreases when the density increases.
Archosaur said:I stand corrected. I suppose I should have done a little googling before posting.
But I think this is a more complicated problem than we're giving it credit. The speed of sound through a medium is directly proportional to the density and temperature of the medium, but density and temperature are inversely proportional to each other. But, if what I'm hearing is right, the increase in molecular velocity outweighs the decrease in speed.
cjl said:Actually, for an ideal gas, the speed of sound is largely independent of density, and it is proportional to the square root of the temperature.
the problem is, what is A above middle C? Concert pitch should (?) depend on ambient temperature.mfb said:Where is the problem?
I'm not sure where you got that equation, but it appears to be missing something. The speed of the molecules should be proportional to the square root of p/ρ, rather than directly proportional. My guess is that your equation (1) should have a c2 rather than simply c. Also, you can't change the density without changing the pressure unless the temperature is also changed, and if you rearrange the density form of the ideal gas equation (P = ρRT), you'll find that T is proportional to P/ρ, so stating that the speed of sound is proportional to the square root of P/ρ (which is the correct relation) is identical to stating it is proportional to the square root of the temperature, as the only way you can change either P or ρ independent of each other is by changing the temperature (for an ideal gas).nowhat said:Hey guys just did some algebraic calculation and got a strange conclusion.
since speed of sound is related to speed of molecule, we can assume they are proportional to each others. Then, according to kinetic theory equation,
pV = 1/3 NMc ...(1)
where c is the rms speed of air molecules, N is number of air molecules, M is mass of each air molecule. i.e. NM = total mass of the gas
please notice that density of air = mass/volume, i.e. ρ = NM/V , where ρ is density
therefore, by rearranging the equation,
c = 3p/ρ
which basically means that the speed of molecule is inversely proportional to density, assuming change in pressure is negligible, which is against most of the arguments above.
sophiecentaur said:But strings don't behave like wind instruments.
The speed of sound is the rate at which sound waves travel through a medium. In dry air at room temperature, the speed of sound is approximately 343 meters per second.
As temperature increases, the speed of sound also increases. This is because sound waves travel faster through warmer air, which has less density and allows the sound waves to move more easily.
The relationship between temperature and the speed of sound is directly proportional. This means that as temperature increases, the speed of sound also increases, and vice versa.
In colder temperatures, air molecules are closer together and have higher density. This makes it more difficult for sound waves to travel through the air, resulting in a slower speed of sound compared to warmer temperatures.
One example is the "crack" sound made when a whip is snapped. When the whip is moved quickly, it creates a low-pressure region that stretches the air molecules apart, causing them to vibrate and create a sound wave. The speed of sound created by the whip is affected by the temperature of the air it travels through. Another example is the Doppler effect, where the pitch of a sound wave changes depending on the relative motion between the source and the listener. Changes in temperature can affect the speed of sound, leading to changes in the pitch of the sound heard by the listener.