Purpose:Demonstrates standing wave resonances in an open tube
Description:This popular toy is available in many stores and students may have seen it before, but this is an opportunity for them to explore how it works. To produce resonant frequencies of the tube, hold the tube by one end, keeping that end free for flow of air, and swing it around your head. Increasing the speed of the rotation raises the harmonic produced. Up to seven harmonics can be produced, illustrating the notes of the overtone series. The fundamental can only be produced by blowing gently into one end.
SUGGESTIONS: Read Invited talk : Sounds Like
Fun, presented by Paul Doherty of the Exploratorium at the 2004 meeting of the AAPT at Sacramento, CA, discussing how the
twirl-a-tune works.