October 2019 Issue,
Volume 87, No. 10
The Fourier spectrum of a singing wine glass
The phenomenon of the singing wineglass is familiar to many. Most people have run a finger along the rim of a wine glass with the right speed and pressure to get it to whistle a tone or perhaps heard a glass harmonica being played. However, have you ever noticed and wondered why the vibrations caused by a finger on a glass produce a pulsating sound, rather than a steady, constant-amplitude vibration? Further exploration reveals that the sound and pulsations of a wine glass vary depending on the way the wine glass is stimulated. In this paper, we investigate and model the characteristic sounds produced by three different cases: the pulsating sound exhibited by a finger run along the rim of a wine glass, the steady tone produced by a stationary finger on a rotating wine glass, and the decaying pulsations exhibited by a struck rotating wine glass. Analyzing the qualitative differences among these three cases provides opportunities for students to hone experimental, modeling, and data analysis skills in an intermediate level undergraduate experimental physics course.
LETTERS TO THE EDITOR
The transit of Mercury: November 11, 2019 by Udo Backhaus. DOI: 10.1119/1.5122743.
BACK OF THE eNVELOPE
Dangerous limits by Sanjoy Mahajan. DOI: 10.1119/1.5125214.
NOTES AND DISCUSSIONS
Uncle Jesse and the seven “early career” ladies of the night by Judith Cohen, Susan Kayser, A. Victoria Peterson, Anneila Sargent, Virginia Trimble and Donna Weistrop. DOI: 10.1119/1.5122880.
Acceleration discontinuities in dry-friction oscillations by Christopher Isaac Larnder. DOI: 10.1119/1.5123455.
Comment on “Calculating fissility without Legendre polynomials” [Am. J. Phys. 87(9) 739–744 (2019)] by B. Cameron Reed. DOI: /10.1119/1.5124223.
Thermodynamics of Benford's first digit law by Don S. Lemons. DOI: 10.1119/1.5116005.
Laminar viscous flow through pipes, related to cross-sectional area and perimeter length by John Lekner. DOI: 10.1119/1.5113573.
Zero range potential approximation in quantum scattering problems by Eliton Popovicz Seidel and Felipe Arretche. DOI: 10.1119/1.5125110.
Cycloidal paths in physics as superpositions of translational and rotational motions by David C. Johnston. DOI: 10.1119/1.5115340.
The forced harmonic oscillator: Coherent states and the RWA by L. O. Castaños and A. Zuñiga-Segundo. DOI: 10.1119/1.5115395.
Faraday induction from point-charge fields by José Arnaldo Redinz. DOI: 10.1119/1.5124977.
The Fourier spectrum of a singing wine glass by Reuben Leatherman, Justin C. Dunlap and Ralf Widenhorn. DOI: 10.1119/1.5124230.
Envelopes, foci, and maxima of special trajectories by Pavlos Mihas. DOI: 10.1119/1.5122894.
Variation of the apparent size of the Sun visualized with basic photographic equipment by Peter Trillenberg. DOI: 10.1119/1.5119510.
Single-pixel camera by Tom A. Kuusela. DOI: 10.1119/1.5122745.
No Shadow of a Doubt: The 1919 Eclipse that Confirmed Einstein's Theory of Relativity by Alexei Kojevnikov. DOI: 10.1119/1.5123052.
American Journal of Physics 87, 852 (2019); https://doi.org/10.1119/1.5124679.
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