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Length of Wavelength in closed aircolumn

  1. Nov 20, 2007 #1
    1. The problem statement, all variables and given/known data

    An 80-cm long air column, closed at one end, contains sounding waves. How long is the wavelength that corresponds to: the first overtune

    2. Relevant equations

    v = f(lambda)

    3. The attempt at a solution

    no clue about what to do.
  2. jcsd
  3. Nov 20, 2007 #2


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    In a pipe with one closed end, the first harmonic (fundamental frequency) has a wavelength that is equal to 4 times the length of the pipe. This is because the closed end acts as as a node and the open end as an anti-node. What will the wavelength of the first overtone then be?
  4. Nov 20, 2007 #3
    For a closed air column, the most simple standing wave that can occur is one with a nodal position at the closed end and an antinodal position at the open end...or 1/4 of a complete wavelength would correspond to the length of the column. Thus lambda = 4L.
    There is a correction factor for the diameter of the pipe, but since you did not include that information, I will assume that the small correction factor is being ignored here.

    Edit to Add...Kurdt beat me to it!
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