Carl Mungan, United States Naval Academy
mungan@usna.edu

The damped oscillations of the water level inside a partly submerged drinking straw are modeled on page 433 of the June 2019 issue of the American Journal of Physics (http://aapt.scitation.org/journal/ajp). Section II of a paper on thermodynamics on page 752 of the September issue gives a particularly helpful treatment (in four equations and a graph) of how to actually use the Lambert W function to find the roots of the transcendental equation in which an exponential equals a linear polynomial. I also found the experimental investigation of different ways to excite a ringing wine glass on page 829 of the October issue to be intriguing and readable.

Charles Babbs has an accessible analysis of the physics of skipping stones on page 278 of the May 2019 issue of The Physics Teacher (http://aapt.scitation.org/journal/pte). I also appreciated Wayne Garver’s discussion of heterodyning on page 312 of the same issue. Many teachers will probably be helped by Dan Styer’s article presenting some convincing examples and arguments for why entropy cannot be considered a measure of “disorder” on page 454 of the October issue.

Article 045402 in the July 2019 issue of the European Journal of Physics presents a new method to analyze the finite square well potential that I am going to try on my students when we get to this topic in my modern physics course this semester. An interesting discussion of applying either the flux rule or the Lorentz force law to the unipolar generator appears in article 055202 of the September issue. Finally, I thought Lemos presented some useful new insights into the calculus of variations problem of the “least uncomfortable” journey between two points in article 055802 of the same issue. Article 045001 in the July 2019 issue of Physics Education presents arguments and experimental evidence that the color of pure water is blue. In comment 056501 in the September issue, Rizcallah presents a simple argument for why the relative speed of impact between two particles is the same before and after a 2D elastic collision, which partly generalizes that well-known result in 1D. Both journals can be accessed online starting at http://iopscience.iop.org/journalList.

Donald Truhlar explains some misconceptions associated with molecular dispersion forces on page 1671 of the August 2019 issue of the Journal of Chemical Education. You may also wish to peruse an informative review of Count Rumford’s cannon boring experiments on page 1955 of the September issue. The journal archives are at http://pubs.acs.org/loi/jceda8.

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.