Will the wavelength decrease when the wave moves from a light string to a heavy

  1. Sep 15, 2005 #1
    hi, i was just wondering if a wave's wavelength will change when it goes from a light string to a heavier one. I think it wouldn't affect it, however I know that velocity will be affected as the linear density will be changed. But am I right, will the wavelength remain unaffected?
     
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  3. Sep 15, 2005 #2

    Tom Mattson

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    You're right that the speed changes. It seems that the essential piece of information that you are missing is this: the frequency does not change.

    So since you know that [itex]v_1=\lambda_1f_1[/itex] and [itex]v_2=\lambda_2f_2[/itex], so what can you say about the wavelengths?
     
  4. Sep 15, 2005 #3
    ok, so that means that although the mass of the string increases, this will have no affect whatsoever on the frequency because since
    v= sqrt(T/linear density) and also (wavelength/tension)
    and increasing the mass of the string will have no affect on the tension, v increases as the tension remains constant, therefore will the wavelength have to INCREASE in order to compensate the equation? Am i on the right track?
     
  5. Sep 15, 2005 #4

    Tom Mattson

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    The first part is right, but the second part is not. v does not equal (wavelength/tension). That expression doesn't even have the right units to be a speed.

    The wave speed decreases as you move to the string of higher mass density.
     
  6. Sep 16, 2005 #5
    oh no, i meant v= (wavelength/PERIOD)
     
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