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What happens to wavelength of sound in liquid?

  1. Feb 16, 2012 #1
    We know that speed of sound in liquid is more than in air.
    Also, velocity of sound = wavelength X frequency.

    Now theres a change in speed of sound from air to liquid, so, wavelength or frequency should have got changed...

    But, generally, frequency won't change for an object (correct me if I'm wrong).
    So there should be a change in wavelength...
    My question is how? The reason?
    (Please try to explain also at molecular level)
  2. jcsd
  3. Feb 16, 2012 #2
    You answered your question already. The wavelength increases because the speed of sound increases. I don't see what you mean by explanation at "molecular level" for this.
    The wavelength is the distance traveled during the time required for the phase to change by 2pi. Nothing to do with molecules.

    If you are looking for an explanation for the increased speed of sound, then you may look at molecular level. The speed is larger in water due to larger bulk modulus (or decreased compressibility). This can be attributed in part to stronger intermolecular interactions and reduced intermolecular space.
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