Bounded by the statements of Feynman and Galileo, I describe certain tricks that can be useful for the teaching of physics. In particular, I describe the calculation of the center of mass (centroid) of an arc of circumference and a circular sector. For this purpose, I also use Pappus's theorems. An Appendix is available with Archimedes' method to…

In nature, we often observe interesting phenomena for which we would like to find a physical explanation. One such phenomenon is presented in this paper.

The Physics Teacher has published over the years many inspiring papers with an historical slant and we agree with Thomas B. Greenslade, who recently wrote that teaching physics is about "integrating physics with human culture.… if we are going to leave a lasting impact on our students, we should do more than teach them pure physics."…

We describe a simple, intuitively appealing interpretation of the observed ellipsoidal shape of the rotating Earth: it is that surface everywhere perpendicular to the net force upon it.

Ion transport, involving the diffusion and migration of ions within the electrolyte, stands as a fundamental concept in electrochemistry and serves as the driving force for electrochemical reactions. Electric double layers are critical in the fields of electrochemical energy storage and chemical conversion, constituting a central focus of…

Forces and motion are at the heart of physics and children start learning from the moment they are able to interact with the world. Children as young as one year show surprise when a ball does not behave as expected. This is a tremendous bonus to learning physics, but it has hidden dangers: they only learn how things move on the Earth, where we…

The Wilson cloud chamber is an apparatus used for detecting and observing the trails of alpha/beta rays or even cosmic rays in saturated gas conditions. The principle of this device is based upon the powerful ionization of the aforementioned rays within the medium. This article will provide instruction for creating a classic version of the cloud…

A classical mechanical structure with an internal degree of freedom is shown to reflect off a potential well. Such behavior is impossible for point-like or rigid classical particles. This numerical study provides insight for students studying internal energy and degrees of freedom.

If a ball rolls in a circular path on a horizontal surface at constant speed then its horizontal rotation axis changes direction with time. A simple experiment is presented showing that the torque applied to the ball is equal to the rate of change of its angular momentum, even though the magnitudes of its angular velocity and angular momentum…

Enrico Fermi is remembered for his many contributions to theoretical and experimental physics, but from an educational point of view he also popularized the use of the kind of questions we now call "Fermi problems" (or "Fermi questions"). Fermi problems (FPs) are back-of-envelope problems that arose from the need to make order…

Experiments involving RC circuits are an integral part of introductory physics courses. Previous articles using RC circuits describe determining the charge on a Van de Graaff generator, measuring currents and voltages in a charging RC circuit using a multimeter or an Arduino, measuring the decay constants of complex RC circuits, and using the…

Acceleration of moving objects is usually measured by photoelectric gates. In this paper, a method of acceleration measurement is proposed by pasting white card stock and black tape on a pulley and then using an Arduino to time the motion. This method only needs one photoelectric sensor to measure the acceleration. In contrast, using photoelectric…

A smartphone is a powerful learning aid in the hands of a large section of students around the world. The camera of the phone can be used for several learning purposes apart from its obvious purpose of photographing. If the focal length of the lens of the camera can be determined, several experiments in optics can be performed with it. In some…

In this article we find the thermodynamics of some large N particles systems and some small N particles classical systems using micro canonical ensemble. Small N particle systems are seldom done in textbooks, since statistical mechanics(SM) systems work for large N systems. We show that small N systems will help the students to get an insight…

In this article, a guide is presented to help biology teachers so that they can process the subject of the eye and eye defects with an interdisciplinary approach. The guide, which was created by considering the stages of a lesson plan, includes content information, suggestions, and various directions that can help the teacher at every stage. The…