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Homework Help: Help with physics resonance

  1. Feb 15, 2006 #1
    There's a metal cylinder from which water is flowing out at a rate of 10^-6 m^3/s. A tuning fork of 300 Hz is placed on top of the cylinder. At what water levels will the first two resonance frequencies be heard?

    It doesn't seem like a difficult problem, and it really isn't. I just can't seem to see it.

    I dont think the flow rate has any signifiance in calculation; it's only useful to know that the water level is decreasing.

    It's an open-closed system, so the natural frequencies are [tex]f_n = \frac{nv}{4L} [/tex] where n = 1, 3, 5, 7....

    So in the first case, i think the first frequency heard would be 300 Hz. Hence, one can solve for [tex]L_1[/tex] to attain 0.286m. But how about for the next? Will it just be 3 times L_1 ? Or how do you solve for it otherwise?


    Question 2: Is it logical to ask whether the beat frequency is e.g. +4 or -4? Afterall, [tex]f_{beat} = |f_2 - f_1| [/tex] so because of the absolute value,it is always +4.
    Last edited by a moderator: Feb 15, 2006
  2. jcsd
  3. Feb 16, 2006 #2

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