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Homework Help: Resonant length

  1. Dec 3, 2006 #1
    1. The problem statement, all variables and given/known data
    The 1st rensonat length of a closed air column occurs when the length is 30.0cm. what will the send ond and third be?

    2. Relevant equations
    I did the pattern thign like 3/4 but i got the wrong answer.

    3. The attempt at a solution

    i multplied the legth 3/4 but i got the wrong answer.
     
  2. jcsd
  3. Dec 3, 2006 #2
    Second = 30.0*3=90.0 (cm)
    Third= 30.0*5 = 150.0(cm)
    u can draw graphs to know why.
     
  4. Dec 4, 2006 #3

    andrevdh

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    Homework Helper

    A node is situated at the closed end an antinode at the open end. The "smallest structure" of the wavelenght that can accomodate this is a quarter wavelength.Which means that the wavelength is 120 cm. The next waveform will be three quarters of a wavelength (again a node at the closed end and an antinode at the open end).
     
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