Question

Musical notes have names (A,B,C, etc). The lowest A on a piano is called A0. If you go up an octave, the next A would be called A1. An octave higher, A2. The A near the middle of the keyboard is A4 (also called "concert A"). A similar pattern is true for all the notes.

In a certain set of organ pipes, the speaking length (that's an effective physical length) for the pipe that makes the note C5 (f=524 Hz) is 32.82 cm. How long a pipe do you expect for C2? Compute your answer in meters, but do not enter units. (If the answer is 850 cm = 8.5 m, enter the number 8.5)

For you to think about: What is the wavelength of sound produced by the C5 pipe described in this problem? It's not the same as the length of the pipe, it should be different by a factor of 2 (that's not an accident, we'll discuss why later). The longest organ pipe in the world (according to my quick web search) is 64 feet long. Based on the numbers in this problem, could you actually hear the sound produced by this pipe? Why or why not? What might be the effect of such a pipe? What would you need to do (lengthen? shorten? by how much?) to this pipe to get a sound with a wavelength twice as long?

Answer 1