PURPOSE: To demonstrate standing wave resonances in an open tube.
DESCRIPTION: 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.
REFERENCES: (PIRA 3D30.35) Use demonstration H3-15: TWIRL-A-TUNE AND VACUUM CLEANER, to create more harmonics, but it is noisy! See Demonstration Reference File for interesting articles on the theory of this device.
SETUP TIME: None.
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