Find the greatest length of an organ pipe open at both ends that will have its fundamental frequency in the normal hearing range (20—20,000 Hz). Speed of sound in air = 340 m s-1.

Given:
Speed of sound in air



We are considering a minimum fundamental frequency of
,
since, for maximum wavelength, the frequency is a minimum.


Length of organ pipe


We have:




We know that:




On substituting the respective values in the above equation, we get:




Length of the organ pipe is 8.5 m.


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