Browsing the Journals
Carl Mungan, United State Naval Academy
Thomas Bensky and Matthew Moelter outline an introductory-level computer analysis of the kinematics and dynamics of a bead sliding on a frictionless wire on page 165 of the March 2013 issue of the American Journal of Physics. Art Hobson argues that the fundamental constituents of relativistic quantum reality are fields, not particles, on page 211 of the same issue. In a short note on page 313 of the April issue, we are reminded of how important it is to keep track of which variables are being kept constant during partial differentiation; that truth is particularly important in statistical mechanics, but the presented example contrasts the partial derivative of the kinetic energy with respect to a generalized coordinate in Lagrangian and Hamiltonian dynamics. Finally, Alejandro Jenkins tells us the history of a fraudulent perpetual motion machine on page 421 of the June issue that fooled even Leibniz and Bernoulli, while Selmke and Cichos draw an instructive analogy between Rutherford and optical scattering on page 405.
The February 2013 issue of The Physics Teacher has various descriptions of useful mechanics experiments: using buoyancy to measure the volume of a helium balloon on page 93 and to consider the change in apparent weight of an immersed object on page 96, and using an Atwood machine to measure dry axle friction in the pulley. On page 155 of the March issue, Frank Wang reminds us that a moving clock may not appear slow, owing to the finite signal propagation time from the clock to the observer. Speaking of motion relative to observers, that is what is important for the force on moving charges in a magnetic field, as discussed on page 169 of the same issue. Steve Iona reviews the 50 years of publication of TPT at the beginning of the April issue, and Mikhail Kagan solves the classic fox and rabbit chase problem by an elegant use of nonorthogonal coordinates on page 215.
A short but accurate calculation of Baumgartner’s velocity of fall starting from 39 km above New Mexico is found on page 139 of the March 2013 issue of Physics Education. Some class demos about surface tension using soap films are presented on page 142. Mark Harrison compares impedance matching of resistors to perfectly inelastic collisions in mechanics on page 207. Ciocca and Wang discuss why moonlight often appears silvery or bluish on page 360 of the May 2013 issue, even though spectroscopically moonlight is redder than sunlight. Also don’t miss the contrast between blowing toward a candle from behind a menu, a wine bottle, or a funnel on pages 414 and 416. David Rowland has written another paper in his series about longitudinal motion for transverse string waves on page 225 of the March 2013 issue of the European Journal of Physics. Both journals can be accessed on the IOP Science website.
I enjoyed Howard DeVoe’s contrast of the local and global formulations of thermodynamics in the May 2013 issue of the Journal of Chemical Education. Be sure not to overlook the online Supporting Information in which he performs a computer-based Eulerian integration of the equations for a pinned vertical piston subject to wet friction (with vacuum on one side and an ideal gas on the other) that is suddenly released while the cylinder is immersed in a constant-temperature fluid reservoir.
If you make the effort to correct the large number of typos, there are some interesting comparisons of the times required for objects to move vertically due to gravity along various special paths on page 398 of the September 2012 issue of the Latin-American Journal of Physics.
The Fall 2012 Newsletter of the Society for College Science Teachers has a Teaching Tip by Paul Dolan in which he discusses the wide range of physics phenomena that can be presented using a ball on a string.
Disclaimer–The articles and opinion pieces found in this issue of the APS Forum on Education Newsletter are not peer refereed and represent solely the views of the authors and not necessarily the views of the APS.