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Sound direction

  1. Dec 26, 2008 #1
    i have been searching for something i am positively sure about but i've been told that i am wrong, i couldn't find anything on the internet...so i thought this to be the best way to find some answers to my question.......

    is it true that sound ...also rises up like heat...???

    pleas answer :)

    thanks in advance !
  2. jcsd
  3. Dec 26, 2008 #2


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    Science Advisor

    No. Sound is due to pressure fluctuations in a medium, i.e. air. It is omnidirectional if left to its own devices. Think of a stone being dropped in water.
  4. Dec 29, 2008 #3
    hmm, and yet sound carries energy (kinetic, of the moving particles) given while producing the sound.

    unlike heat (chaotic movement), sound is directional movement, consisting of wavefronts, and does not stay in one place (sound is heard outside the room where it was produced, disperses away)
  5. Dec 31, 2008 #4
    Wow, I actually find myself (sort of) disagreeing with a Science Advisor here. :wink:

    In a medium with a temperature gradient (for example, a mass of air that is hotter at the bottom than the top), sound waves tend to bend toward the colder part. Why? Because the speed of sound varies with temperature! Cooler air conducts sound more slowly. Therefore, if air closer to the ground is warmer, then sound waves will bend upward. If air closer to the ground is cooler, sound waves will bend downwards, and will even bounce along the ground as shown here: http://www.physics.uiowa.edu/adventure/spr_2006/feb_4-06.html [Broken] (scroll down to "refraction")
    Last edited by a moderator: May 3, 2017
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