I would like to know how sound travels through gases.?

Question

i am kindly asking you not to direct me to another site because i have tried but failed.thank you.

Answer 1

Okay, gas is basically just a more energetic medium than a solid, yeah? It has more free space in it, butit also ascribes to the same laws of motion, kinetics, pressure, fluid dynamics, basically.

So, essentially, what happens is that a source emits a sound. What is a sound? Well, it's a wave. But more specifically, it's a pressurized region in the material it's traveling through, with specific velocities (a combination of speed or distance traveled AND direction)...

In this example we'll just consider a straight wave without and dispersion (doesn't really happen under most circumstances, but is good for a simple thought experiment).

What happens is you get pressure at the originating point, and the pressure or motion is in a specific direction. So, the molecules/atoms of the medium get pressurized, or squeezed together by the more energetic molecules coming from the source of the sound.

Now, I think it was newton {?} that said for every action there is an equal and opposite reaction. So, the molecules being pushed push back on the molecules from the sound source, effectively stopping those molecules. But! And here's the rub... conservation of energy says that energy can't be created or destroyed, only change forms. Well, in this case, the molecules that got hit by the sound source are imparted with the energy of the the molecules they stopped. So, now they're moving in the direction the original sound was moving, until they hit more molecules.

When they hit more molecules, they transfer their energy to the new molecules and they hemselves stop. The new molecules keep on going in this manner until they hit more molecules. And so on and so on.

So, the wave of pressure keeps on moving until either it dissipates, or it encounters an equal and/or opposite wave of pressure going the other direction.

If they're equal, they cancel each other out, if the other wave is stronger, then the net effect is that whatever energy wasn't canceled out moves in the direction the other waves was going.

But long and short, a source exerts a bunch of energy and creates molecules that are very energetic and compressed and want to expand. But since they have a direction too, they try to expand in that direction. Thus they create a compressed and energetic set of particles going that way and ipart their energy and direction on those particles.

Now realistically, this happens in three dimensions(up and down, left and right, backward and forward; or just length, width and height) and not just one, so a sound source will generally move in 3 dimensions or in a sphere. And the further away from a source the sound gets, the weaker it gets in any one direction, since the same amount of energy is covering more and more territory. And you can't create or destroy energy, so you have to divide the total energy by the total surface area. So the total energy arriving at any one destination tends to be much weaker than the sound when it was initially released from the source...

Answer 2

Responder edthescienceguy is not correct: the density of the gas has nothing to do with the speed of sound. It is not how many molecules there are, but rather how fast they move. And in a gas, that depends on the absolute temperature. Since the speed of motion is proportional to the square root of the absolute temperature, the speed of sound is also. The speed of sound is not exactly equal to the mean molecular speed -- there is a geometrical factor which shows up when you grind out the math.

Suppose that you have a diaphragm in a gas, and you give it a push. This will compress the gas in front, and the compression wave will propagate as the molecules move. When you release the push, everything moves back to where it began. At some distant point, the compressions and rarefactions can be perceived as sound.

Answer 3

I dont understand your question.

If you are asking the mechanism by which sound is transmitted then its compression waves that carry momentum along that travel through the medium. when the molecules carrying the momentum bump slower moving molecules there is a hand-off of the momentum, and the slower (now faster) molecules are now carrying the momentum. Its like an insanely large bucket brigade in 3 dimensions, and the full buckets start at the sound source and go outward.

If you are asking for the math it can be really complex. Its useful, and not impossible to manipulate, but if you havent learned the jargon its going to be hard to get in one answer.

Answer 4

Same way it travels through any medium, by vibration of the molecules. The sound energy travel slower in gases as the molecules are farther apart. The more dense the material, the faster the sound waves move

Answer 5

Sound travels in compression waves caused by virbating surfaces.

Answer 6

repeating your call doesnt help everyone. plasma includes plenty potential that the sound is vaporized. repeating your call doesnt help everyone. plasma includes plenty potential that the sound is vaporized.

Answer 7

i think its by vibrartion

Answer 8

no clue