Tuning Forks And Resonant Tube
To illustrate resonance in an air column.
Plastic tube with resonant and non-resonant tuning forks.
Strike either tuning fork and hold it to the end of the tube. The sound intensity of the fork at the resonant frequency of the tube increases dramatically, whereas the fork with the non-resonant frequency does not become significantly louder. The second harmonic of the tube is excited.◙
Thomas D. Rossing, Daniel A. Russell and David E. Brown, On the acoustics of tuning forks, AJP 60, 620-626 (1992). Bruce Denardo and Miguel Bernard, Design and measurements of variably nonuniform acoustic resonators, AJP 64, 745-751 (1996).