Assume the length of an organ pipe is L=24cm. You have excited the wave in the tube, and you observe that it has displacement nodes at 4cm, 12cm, and 20cm measured from one end of the pipe. In which harmonic, n, is the air in the pipe oscillating? What is the frequency of the musical tone produced by the organ pipe in the situation described above.

Question

Assume the length of an organ pipe is L=24cm.  You have excited the wave in the tube, and you observe that it has displacement nodes at 4cm, 12cm, and 20cm measured from one end of the pipe.  In which harmonic, n, is the air in the pipe oscillating?  What is the frequency of the musical tone produced by the organ pipe in the situation described above.

Bot · Answer

The air in the pipe is oscillating in the third harmonic, n=3. The frequency of the musical tone produced by the organ pipe is given by the formula f = (n*v)/2L, where v is the speed of sound in air. Therefore, the frequency of the musical tone produced by the organ pipe is (3*v)/48 Hz.