The interference pattern between two harmonic oscillations with slightly different frequencies are called beats. The beats, as a combined motion, have two different periods, one approximately equal to the period of the original oscillations, and another that is significantly longer and is related to the variable amplitude of the motion. The main…

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…

Light and its spectrum are central concepts in many introductory physics, astronomy, geology, and conceptual physics courses. The Sun and its spectrum are usually primary examples, likely due to the Sun's everyday familiarity and the full spectrum it generates when dispersed. To enhance such discussions with a hands-on student activity, we've…

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 reflection and refraction of light are more familiar to students than the reflection and refraction of sound. Reflection and refraction that occur during the transmission of sound waves are common phenomena in everyday life but are often difficult to understand during actual learning. In this study, we developed a sound reflection and…

The weight, one of the key concepts of physics education, still continues to be discussed among physics educators. Today, there are two main definitions as the 'gravitational' and 'operational', but there are differences even between them. It is important to know the different approaches found in textbooks in eliminating misconceptions and…

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…

Ever wonder how an astronaut's mass is measured in space? Of course, a weight scale is of no use, because the astronaut and the scale are in free fall. Measuring the period of a spring mass oscillator is one way to measure mass. In this article, we will demonstrate a method to measure mass using a smartphone, a rubber band, and an app called…

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…

Recently I took a walk through the physics demonstration room at Kenyon College, where I first started teaching in 1964. On an upper shelf was the little home-built apparatus in Fig. 1. This was used for one of two short single-concept films that I made in the 1970s. Both "The Magnus Effect" and "Optical Barrier Penetration"…

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…

Why does a raindrop on a window pane show an image of the environment that is turned upside-down? And why does vision go blurry underwater, but is perfectly clear with diving goggles? Our everyday life is rich in optical phenomena. Unfortunately, these phenomena often play a subordinate role in Optics teaching, compared to ray constructions or…

A rocket must carry the fuel it expels in order to accelerate its structure and payload. The rocket equation relates the change in speed to the fuel mass expelled. To launch a spacecraft into Earth orbit requires a multi-stage rocket, since otherwise the mass of fuel required would be prohibitive. While the details vary among historical and…

In this commentary, I consider several theoretical and methodological aspects of Nadaraji Govender and Edson Mudzamiri's study. The commentary starts with an examination of the purpose for making physics understandable to learners of indigenous background and decolonization of school physics in Govender and Mudzamiri. Next, I offer an alternative…

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…