Student understanding of the laws that describe the flow of a fluid is often hampered by a defective knowledge of basic classical mechanics (kinematics, statics, dynamics, and conservation laws) and by wrong common-sense ideas about quantities related to fluids, such as velocity and pressure. A pedagogical discussion about the Venturi effect,…

Sound is an interesting topic for physics lessons at all ages. However, it is difficult to illustrate this ubiquitous phenomenon and many models do not adequately represent the properties of sound and thus promote unwanted conceptions. The experiment presented here avoids this by visualising sound itself with the help of the schlieren technique.…

Electrochemical and spectroelectrochemical techniques are very important for characterizing energy materials. In the search for new sources of renewable energy, water splitting for hydrogen production and CO[subscript 2] reduction is attracting significant attention. These applications require efficient and durable catalysts and a detailed…

Tungsten oxide semiconductors are used to photooxidize water. Students prepare WO3, CuWO4, and mixed composition thin film photoanodes. The syntheses are simple, allowing for the quick production of a range of materials. Photoanodes are tested in a photoelectrochemical cell assembled from common equipment, allowing for the direct comparison of…

In this paper I explain how I usually introduce the Schrödinger equation during the quantum mechanics course. My preferred method is the chronological one. Since the Schrödinger equation belongs to a special case of wave equations I start the course with introducing the wave equation. The Schrödinger equation is derived with the help of the two…

The Briggs-Rauscher reaction is a popular demonstration to illustrate chemical oscillations in laboratories, classrooms, and public seminars because of its simplicity and visual appeal. Here, we adapt the Briggs-Rauscher reaction to present reaction-diffusion-convection patterns in the undergraduate general or physical chemistry laboratory. By…

Society at large often incorrectly thinks that the word 'chemicals' implies danger, when of course all matter can be described as a chemical. In this article we define what precisely we mean by 'hazard', risk' and 'danger'; we then consider selected elements from the periodic table that are noteworthy because of their dangerous characteristics.

A spinning top with a spherical bottom end was constructed to examine its behaviour. Experimental results were consistent with theoretical predictions.

In this paper we derive and discuss the time it takes for a force to turn a velocity. More precisely, we derive the formula for the time t it takes a constant force that makes an angle a with the initial velocity v(0) to have v(Tau) get within an angle ? < a of the force. We then show how the addition of a viscous force decreases Tau…

The construction of a linear speaker array, which emits coherent sound radiation from multiple sources, is described. The device is an improvement over the two-speaker systems for demonstrating wave interference effects. The operation of the array is demonstrated with example data.

There exist several two- and three-dimensional graphical representations of hydrogen-like orbitals. Despite this, connecting the mathematical form of the atomic orbital, a function of both radial and angular variables, to its actual shape is often challenging for students. Here, we present a new graphical representation using bubble plots to show…

The PhiTOP® (or FTOP®) is a physics toy designed not only to act as a spinning top but also to appeal to the eye and to the scientifically curious mind.1 It is currently made in two versions, one from solid aluminum and the other solid brass. Each top is highly polished, and is elliptical in one cross section and circular in another. Its name…

The High Road/Low Road race is often used as a qualitative prediction activity. A marble is released simultaneously on two elevated tracks that differ only in the middle section where the Low Road dips before finishing at the same height as the High Road. Typically a minority of students correctly predict that the Low Road will finish first. In…

All physics is fascinating, but some stories are more exciting than others. A story that involves some of the most precise measurements ever made and a tantalizing discrepancy might be one of the most interesting. Throw in a 3200-mile journey, a heavily laden truck covered by a tarpaulin, closed-down highways with police escorts, and hushed…

Electromagnetic induction, represented by either Faraday's law or the Lorentz force law, produces many paradoxes requiring careful examination and application of these laws. The paradoxical example of induction, presented herein, arose in a class and is resolved within the framework of special relativity.