Purpose:Demonstrate standing wave resonances in an open tube.
Description:To produce resonant frequencies of the tube, hold the end with the cork up to the input of the vacuum cleaner. As you cover the vacuum input more and more with the cork, more air will be pulled through the Twirl-a-Tune, exciting higher harmonics. Up to around 16 harmonics can be obtained.
Note that this demonstration is very loud, and should not be used for very long or in a small, enclosed space. For smaller classes or for extended analysis and discussion, consider other demonstrations from this section.