Day 171: Whirly Tubes
College-Prep Physics: A student project investigating the relationship between the rotational speed of a whirly tube and the pitch produced. The student used a Vernier microphone and Logger Pro to produce an FFT graph which indicated the pitch of the note produced. The student used the video camera on her iPhone to record the twirling so she could get an accurate number for the rotational speed in RPMs.
You can read more about the physics of whirly tubes here: http://www.exo.net/~pauld/summer_institute/summer_day13music/Whirly.html