An acoustics researcher is investigating the resonant sound produced by blowing across the top of a narrow glass cylinder. By adjusting the volume of water inside the cylinder, she varies the height of the vibrating air column. The resulting sound is captured by a digital microphone connected to a spectrum analyzer.
Explain what is meant by the pitch of a sound.
The researcher measures the height of the air column and the fundamental frequency of the signal from the microphone.
Name two instruments that she needs to obtain these measurements.
Identify the dependent variable and the independent variable in this investigation.
The researcher collects the following preliminary data:
| Height of air column (cm\text{cm}cm) | Fundamental frequency of signal (Hz\text{Hz}Hz) |
|---|---|
| 15.0 | 565 |
| 30.0 | 283 |
Suggest three ways in which the researcher could improve her investigation.