Organ pipe A, with both
ends open, has a fundamental frequency of 20 Hz. The third harmonic of organ
pipe B, with one end closed has the same frequency as the second harmonic of
pipe A. How long is pipe B?
Speed of sound in air vair
= 343 m/s.
Since organ pipe A is
open at both ends, the resonant frequencies must satisfy the relationship
where v is the speed of sound in air and LA
is the length of pipe A. For the fundamental
frequency, n = 1 and the frequency is
Organ pipe B is closed at one end. The resonant frequencies are given by
where v is the
speed of sound in air and LB is the length of pipe B. We know that