Standing waves in strings and air columns are studied. Using a sine wave generator to drive a string vibrator, the driving frequency, the length, density, and tension of the string are varied to explore standing waves in strings and to determine the speed of the wave. For the sound waves in the air column, a speaker is used to drive a resonance tube. The driving frequency and the length of the tube are varied for both open and closed tubes. The relationship between resonant frequency modes and tube length is determined for closed versus open tubes.
The frequency of the vibration of the string is not limited to the line frequency so the frequency can be varied, as well as the length and the tension.