The purpose of this publication is to present a novel approach to the demonstration of the Dzhanibekov effect. The main idea of our version is to use a lightweight spinning top of a spherical external form but distinct principal moments of inertia floating in the upward flow of air. As a result, the Dzhanibekov effect can be easily demonstrated…

Vector cross product transformations are essential components in general physics. The numerous mnemonic devices catered towards each potential transformation result in confusion, defeating their purpose of reducing learning barriers. Therefore, a general mnemonic device, subject-environment interaction or the subject, is proposed to help students…

The first of the two postulates of relativity states that the laws of physics are the same in all inertial reference frames. Often it is assumed that the postulates are mainly concerned with objects moving at a significant fraction of the speed of light. However, the postulates are applicable at all speeds from a snail to a photon. To practically…

The purpose of this study is to consider Superman's acts against impulse-momentum and conservation of momentum principles. Superheroes as fantasy fiction characters attract the attention of not only children and teenagers but also adults. Superheroes can be useful in explaining a phenomenon, as well as overcoming conceptual difficulties that may…

High school students' difficulties with quantum physics (QP) are partly due to their limited understanding of the nature of science (NOS). The essence of QP can only be understood with informed views about NOS aspects such as the role of models and the relevance of controversies between physicists. Inversely, QP is an ideal topic for teaching…

Archimedes' principle is one of the foundation subjects in physics. Normally the principle is exemplified by reference to floating boats. However, Archimedes' principle also applies to objects embedded in waterlogged ground, which can lead to the surprising result of an object weighing several tons being lifted. A practical example is presented of…

Although learning about Nature of Science (NOS) promotes a variety of important outcomes, teachers often lack suitable activities for younger students to effectively address NOS. In this article I elaborate on an NOS activity developed for a teacher professionalisation workshop. The activity is suited for younger students as well, where clear…

Students' understanding of forces in circular motion is often incomplete. The problems are not limited to confusions about centripetal acceleration and centrifugal forces. This paper considers possible effects of different interventions by a teacher who has discovered the many types of free-body diagrams drawn by students for circular motion in a…

Huygens' principle in which every point on a propagating wave acts like a point source of radiation is a foundation principle of physics. Normally, Huygens' principle is demonstrated by passing a wave, for example a water or light wave through an aperture comparable in size to the wavelength. In this paper, an experiment is described in which a…

At the end of the 18th-century, Charles Coulomb developed an apparatus to study the force between two electrified beads which allowed him to obtain his famous Coulomb's law. Today, as one of the most fundamental outcomes in classical electromagnetism, his result is revisited in most high school physics courses, where students are asked to…

This paper examines the Torricelli law for the flow of liquid from a small drain hole in a container. It shows how the system can be modelled using either a traditional calculus-based approach or a non-calculus step-wise computer method appropriate to the background of the student group. An experiment to measure the head of out-flowing liquid as a…

We report on the study of student difficulties regarding a heat engine in the context of a Stirling cycle by the method of measurement. An in-class test about a Stirling engine with a regenerator was taken by three classes, and the students were asked to perform one of the most basic activities--calculate the efficiency of the heat engine. Our…

In this article we consider the well-known demonstration of friction by two interleaved books. We consider a factor that has not been part of the popular explanation--atmospheric pressure. We provide three control experiments to demonstrate the role of atmospheric pressure in the two-book experiment and an additional simple demonstration of the…

An online HTML5 Fourier synthesizer app is provided that allows students to manipulate sixteen harmonics and construct periodic waves. Students can set the amplitudes and phases for each harmonic, seeing the resulting waveforms and hearing the sounds. Five waveform presets are included: sine, triangle, square, ramp (sawtooth), and pulse train. The…

In most high school physics classes, gravity is described as an attractive force between two masses as formulated by Newton over 300 years ago. Einstein's general theory of relativity implies that gravitational effects are instead the result of a "curvature" of space-time. However, explaining why things fall without resorting to Newton's…