A closed-pipe resonator has a length of 1.73 m. The frequency of its second harmonic if the speed of sound is 343 m/s is: a)49,5 Hz b)99.13 Hz c)20.6 Hz d)72 Hz

There is no answer, since a closed-pipe resonator can NOT have a second harmonic. However, if you were to plug the pipe length and the speed of sound into the closed-pipe equation anyway you would get 49.56 as your fundamental frequency, which means that 99.13 would be your "plug and play" 2nd harmonic.

Explanation:

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