This isn't actually a homework/coursework question, but rather a need to clarify a discepancy between my lecturer's notes and a textbook.(adsbygoogle = window.adsbygoogle || []).push({});

My lecturer's notes state that for an "organ" pipe, closed at one end, the 1st harmonic frequency will be 4L. For the 2nd harmonic the frequency will be 4L/3. And for the 3rd harmonic the frequency will be 4L/5. (Where L is the length of the organ pipe)

However, in my textbook it denotes these same frequencies as the 1st, 3rd and 5th harmonic, rather than 1st, 2nd and 3rd. Which is the correct formula? My lecturer's or my textbook's? (see attached image from textbook)

--- Sorry, correction: I meant wavelength in all above cases, not frequency. ---

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# Homework Help: Closed Pipe Harmonics

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