On April 14, 1912, the British passenger liner R.M.S. "Titanic" struck an iceberg. The ship sank in a fraction of the time designers had estimated following a worst case scenario. The purpose of this article is to examine the atmospheric refractive phenomena that might have played a significant role in obscuring the iceberg from…

In this article, we construct a very simple double pendulum (the concept of a pendulum should be familiar to all beginning students of classical mechanics). Since a double pendulum has two degrees of freedom, we suggest that this pendulum can be used in the classroom environment to illustrate the concept of normal modes, and we use video software…

The cross diagram is a way to illustrate and plan the solutions for all kinds of constant-acceleration kinematics problems--including projectile motion, multistage, and multiple-object problems. The cross diagram arranges the kinematic variables in a logical way, making the kinematic relationships between them easy to identify. Combined with a…

The Edison Institute predicts that there will be at least 19 × 10[superscript 6] all-electric vehicles (EVs) in use by 2030. This will produce significant effects on our transportation system and its energy requirements. Investigating these effects is an ideal activity to show the relevance of physics. How efficient are EVs in using energy? What…

Teaching special relativity to lower-division students is challenging because results such as time dilation, length contraction, and frame dependence of simultaneity are counterintuitive. The literature is extensive, so only a brief list is given here, with articles divided roughly between discussions of general principles and calculations applied…

Historically, classical thermodynamics was developed during attempts to improve the efficiency of steam engines. Those investigations led to the well-known zeroth, first, and second laws of thermodynamics. Although these laws are presented independently, linkages between the zeroth and second laws have been pointed out in the physics teaching…

We sought to improve concept application in introductory mechanics by emphasizing causal statements (such as "forces change momentum") instead of laws (such as [delta]p=F[delta]t). Using student performance on a well-documented question, this intervention showed modest improvements. However, students in classes using recently introduced…

This work provides a missing manual needed to understand permanent magnets (also known as "hard" magnets), the only source of "magnetic induction field B" (units of teslas), often called the magnetic field, that students are familiar with when they confront magnetic force acting on moving charges. Students see this magnetic…

Many physics teachers have experienced the challenges of implementing the Next Generation Science Standards (NGSS) in their high school curricula. These standards, based upon the Framework for K-12 Science Education, were intended to shift science instruction towards an interdisciplinary focus on three-dimensional learning, phenomena anchored…

Due to the COVID-19 outbreak, academic institutions across the globe have been forced to move to online learning environments. It has been particularly challenging for the experimental sciences to develop and deliver authentic lab-based experiences. Some of the strategies that have been adopted for first-year physics labs include: providing a…

An individual harmonic wave (i.e., having a single frequency and wavelength over all time and space) traveling in a loss-free medium has a single constant speed, which is equal to the magnitude of the phase velocity of the wave. However, when a set of different harmonic waves are traveling in the same direction, they interfere to form wave…

This article analyzes and experimentally verifies the stability behavior of the equilibrium states of a conical pendulum. An analysis of the motion presents that the equilibrium states of the pendulum are determined by the pendulum angular speed. For a given pendulum length there exists a critical angular speed that determines stability…

The overhead projector is perhaps passing out of use, but it is still a useful device with which to do lecture demonstrations. In my early years at Kenyon I was teaching the pre-med course, and found that the overhead projector was an ideal platform for showing the phenomena of polarized light. This note is a discussion of how I learned to use the…

Many readers of this journal are probably familiar with calls from governmental, business, and educational authorities to expand and improve the preparation of science teachers, with a particular focus on the shortage of highly qualified physics teachers. It may seem as if this problem has been around forever, and in fact similar expressions of…

Graphs are an important component in physics laboratory reports. We have noticed that our students have difficulty selecting the "scale" and the "starting value" for an axis while generating graphs on graph paper. Recommendations concerning convenient scales and starting values are found in textbooks, laboratory manuals, and…