Highest to lowest in pitch: A, C, B. This is a hands-on demonstration. Try this with your friends, and be prepared to explain the physics of the demonstration to them.
Work Step by Step
In this experiment, you investigate how the length of a closed-end air column affects the natural frequency of the column. It is helpful to look at Figure 21.5 when answering this question. It turns out that the longer the air column, the lower the frequency and the pitch. Why? The longer air column has a longer-wavelength standing wave. The wave speed stays the same, and is equal to the wavelength multiplied by the frequency. The wavelength is longer, so the frequency is shorter. In summary, the longer the air column, the lower the frequency and the lower the pitch. The air column resonates with your blowing action. You find that the pitch of the note falls as you take away water and make the air column longer.