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Homework Help: Sound coming out of slide whistle

  1. Feb 6, 2005 #1
    A slide whistle has a length of 27 cm. if you want ot play a note one octave higher the whistle should be how long?


    Ans : 1/2 lambda = L

    there Lambda = 2L
    = (2)(27)
    = 54 m

    is that correct?
     
  2. jcsd
  3. Feb 6, 2005 #2

    Galileo

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    That's a rather long whistle.
    And the higher the frequency, the shorter the wavelength, so the whistle should be shorter if it's to produce a higher note.
     
  4. Feb 6, 2005 #3
    so it would be 27/2 = 13.5 m?

    thanks
     
  5. Feb 7, 2005 #4

    Galileo

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    13.5 m is also a tad long for a whistle. It'll look more like a digderidoo.
    The length of the slide whistle was given in cm, not in meters.
    I assume the whistle acts like a half open tube where waves have a node on the closed end and have a maximum at the open end, then the whistle should be half as long.
     
  6. Feb 7, 2005 #5

    HallsofIvy

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    What, exactly, was the original length of the whistle? (Be Careful!)
     
  7. Feb 7, 2005 #6
    my bad.. so the answer is (.27)(2) = .54m?
     
  8. Feb 7, 2005 #7

    HallsofIvy

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    Except that you are going the wrong way again: a longer wave length gives a lower frequency.

    Since the original length was given as "27 cm.", I would be inclined to give the answer as 13.5 cm.
     
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