February 2019 issue of American Journal of Phyics

February 2019 Issue,
Volume 87, No. 2


The mysterious spinning cylinder—Rigid-body motion that is full of surprises

We explore the steady-state rotational motion of a cylinder on a flat horizontal surface from a pedagogical perspective. We show that the cylinder's inclination angle depends on its rotational velocity in a surprisingly subtle manner, including both stable and unstable solutions as well as a forbidden region with no (real) solutions. Moreover, the cylinder's behavior undergoes a qualitative change as the aspect ratio decreases below a critical value. Using a high-speed video, we measure the inclination angle as a function of rotation speed and demonstrate good agreement with the theoretical predictions. All aspects of the analysis are well within the capabilities of undergraduate students, making this an ideal system to explore in courses or as an independent project.



The mysterious spinning cylinder—Rigid-body motion that is full of surprises by David P. Jackson, Julia Huddy, Adam Baldoni, and William Boyes. DOI: 10.1119/1.5086391

Entangle me! A game to demonstrate the principles of quantum mechanics by Andrea López-Incera, and Wolfgang Dür. DOI: 10.1119/1.5086275

Deformation of an inflated bicycle tire when loaded by Jordi Renart, and Pere Roura-Grabulosa. DOI: 10.1119/1.5086008

Manual timing in physics experiments: Error and uncertainty by David A. Faux, and Janet Godolphin. DOI: 10.1119/1.5085437

Nonlinear effect of forced harmonic oscillator subject to sliding friction and simulation by a simple nonlinear circuit by Qian Xu, Wenkai Fan, Yao Luo, Sihui Wang, and Hongjian Jiang. DOI: 10.1119/1.5082534

Shortcut to stationary regimes: A simple experimental demonstration by S. Faure, S. Ciliberto, E. Trizac, and D. Guéry-Odelin. DOI: 10.1119/1.5082933

On the determination of accelerometer positions within host devices by Christopher Isaac Larnder, and Brian Larade. DOI: 10.1119/1.5082536

Modeling the effect of air-intake aperture size in the ping-pong ball cannon by Derek J. Thuecks, and Harrison A. Demas. DOI: 10.1119/1.5086614

Energy conservation in explicit solutions as a simple illustration of Noether's theorem by Markus Pössel. DOI: 10.1119/1.5086003


Comment on “Relativistic particle dynamics without relativity” [Am. J. Phys. 86, 747–749 (2018)] by S. Di Matteo. DOI: 10.1119/1.5086004


Dipoles in quantum field theory by William Miyahira, and David C. Latimer. DOI: 10.1119/1.5086009


Electromagnetic field visualization in virtual reality by J. Franklin, and Andrew Ryder. DOI: 10.1119/1.5080224

Book Reviews

Lost in Math: How Beauty Leads Physics Astray by Moira I. Gresham. DOI: 10.1119/1.5086393

About AJP

General Information, Resources for Authors, Reviewers, and Readers

Additional Resources