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…

In this work, we present an experimental approximation to the study of the phenomenon of radioactivity in secondary schools, taking as an analogy the process of release of carbon dioxide in a carbonated beverage. In this way, we intend to facilitate the approach to the mathematical formalism and to the graphical description of this phenomenon, as…

The ideal gas law, "PV = nRT," is one of the simplest physical laws in nature that is introduced to students as early as in high school and first year in college. In this equation, "P" stands for pressure, "V" is the volume, "n" is the amount expressed in mole, "T" is the temperature in Kelvin…

Two well-regarded measurements for the expansion rate of the universe disagree, leaving cosmologists very puzzled. It may be that something large has been overlooked in our theory of the Big Bang. This discrepancy is called the Hubble tension and it has led to a very interesting conversation within the cosmology community.

It's not surprising that rainbows have received a great deal of attention: in textbooks, in magazines, and on the web. They are, after all, beautiful, fascinating, occasionally awe-inspiring, even a little mysterious. They are an almost perfect blend of natural beauty and simple physics. Has everything that can be said about rainbows already been…

Two bodies initially at different temperatures gathered into an isolated container exchange heat and reach an equilibrium state with a common final temperature. During the process, the system is out of equilibrium and its intermediate temperature is not well defined. By conceiving a quasi-static process with infinitesimal steps from the initial to…

For several years, I taught a general education course on the Manhattan Project for students majoring in the arts and humanities who needed a physical science credit as a condition of their graduation requirements. As might be imagined, the challenge in teaching this course was to find a balance between quantitative and qualitative content. A…

Throughout time people have been measuring the rising and setting positions of celestial objects with respect to the horizon. The motivation for this paper is to provide a link between mathematical and observational approximations for the Sun's declination (angular distance from the celestial equator). One source had students do an experiment with…

It is common for high school physics teachers to comment on the challenges they face in supporting students' graph drawing skills, knowing their importance for the study of physics. This paper suggests a novel and alternative way to support students to develop their graph drawing skills as well as teach them about sound, frequency, and amplitude.…

The lesson presented here provides a multifaceted inquiry-based opportunity to develop a deep grasp of Archimedes' principle. It was originally developed for high school teachers as part of their training in the basic structure of the Next Generation Science Standards. There are numerous demonstrations illustrating Archimedes' principle, many of…

Quadcopters (also known as "drones") do not fly in vacuum. This is obvious enough that experimenting on one in a vacuum chamber would seem rather uninteresting, but there is one question that may be usefully addressed by such an experiment: the mechanism for yaw control. Quadcopters control yaw (rotation about the vertical axis) by…

Traditional school laboratory exercises on a system of moving objects connected by strings involve deriving expressions for the system acceleration, a = (?F)/m, and sketching a graph of acceleration vs. force. While being in the form of rational functions, these expressions present great opportunities for broadening the scope of the analysis by…

The goal of this paper is to illustrate different ways that cardsorting activities (or "card stacks") can be implemented in the introductory physics classroom, along with various tips and resources for getting started. My first attempt at developing a card stack came about from simply wanting to try out a fun way to change student…

This paper is an addition to the series of papers on the exponential function begun by Albert Bartlett. In particular, we ask how the graph of the exponential function y = e[superscript -t/t] would appear if y were plotted versus ln t rather than the normal practice of plotting ln y versus t. In answering this question, we find a new way to…

With a rod, cord, pulleys, and slotted masses, students can observe and graph exponential growth in the cord tension over a factor of increase as large as several hundred. This experiment is adaptable for use either in algebra-based or calculus-based physics courses, fitting naturally with the study of sliding friction. Significant parts of the…