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Soundwaves question

  1. Oct 26, 2009 #1
    A little question I hope you can help me with.
    If you got the low frequency bass notes and some high notes as well.
    Then you have the formula:
    v = [tex]\lambda[/tex]*f

    A quick calculation gives you a wavelength of 34,3 m for af 10 Hz soundwave and 1.715 cm for a 20.000 Hz soundwave.

    Does that mean that I would need a 34,4 m wall to stop the waves of a 10 Hz soundwave, if we imagine that wall being infinitetly tall and wide, and then only 1.716 cm wall to stop the waves from a 20.000 Hz soundwave ?

    Or is there some other factors that play along ?


    Regards
     
  2. jcsd
  3. Oct 26, 2009 #2
    Presumably you worked out the wavelength in air.

    Have you thought that the speed of sound might change in the wall?
     
  4. Oct 26, 2009 #3
    I've thought of that yes. But do you have to calculate the wall-thickness depending on the material that the wall is made of ?
    So if the wall is made of material that doubles the speed of sound, compared to air, the wavelength doubles and you need a thicker wall ?
    Or is it a mixture of both ? :S
     
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