This paper describes two examples of teaching situations in which the idea of infinity arises, and supports the conclusion that infinity is not a physical reality but a very powerful and useful mathematical device which facilitates modelling and the solution of problems in physics.

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

The udu is a traditional Nigerian percussion instrument that can be thought of as a Helmholtz resonator with two apertures. We use a simple two-particle mechanical analogue to study the behaviour of such a resonator and find that the model describes quite well the main features of udu acoustics.

We present a simple activity based on the liquid-drop model which allows secondary school students to explore the uses of mathematical models and gain an intuitive understanding of the concept of binding energy, and in particular the significance of positive binding energy. Using spreadsheets provided as supplementary material, students can…

Simple energy balance models of planetary systems are of fundamental importance to understanding equilibrium temperatures. Most textbooks that discuss energy balance take a further step and include the effects of an atmosphere on the surface temperature. It is noticeable, however, that in such discussions of planetary surface energy balance some…

The purpose of this publication is to bring attention to some physics problems whose answers seem to be paradoxical and, at first glance, do not agree with a limiting case check. Solving a problem on the motion of a system consisting of two masses and a spring, it is natural to examine the answer by considering a case when a spring constant is…

In this article, we propose a simple and accessible model of a magnetic levitator fitted with a Hall sensor. This model also allows to determine the magnitude of the magnetic field within the levitator working volume. Students can also compare the experimental magnetic field values to reference values in magnetism textbooks. This Arduino-based…

Is a suction cup at the bottom of a bathtub subject to an upward force from the surrounding water, even if there is no water under it? A student question, posted in a teacher facebook group on a Monday morning, led to a discussion involving 21 comments with 225 replies offered by 16 teachers during the next few days, including several simple…

An apparatus of the 70s for measuring thermal conductivity in different materials is used to visualize, through an infrared thermal imaging approach, temperature fields and the heat diffusion process. The observed temperature profiles also suggest solid grounds for a fair mathematical modelling of this phenomenon.

It is often necessary to enrich the teaching environment in order for students to learn optics in depth and to interpret the real optical situations with the information they have learned. In this study, a virtual teaching environment was developed using by Algodoo, a 2D simulation software. An eye model was created in order to explain the…

In recent years, general relativity (GR) and gravitational-wave astronomy have emerged both as active fields of research and as popular topics in physics classrooms. Teachers can choose from an increasing number of modern instructional models to introduce students to relativistic ideas. However, the true potential of an instructional model can…

This paper shows how two distinct but related models can be used to bring out the essential physics of heat flow in one dimension. The first is a simple step-wise procedure using "SMath Studio," while the second is an electric analogue using a basic RC ladder connected to an Arduino microcontroller. Both models can be demonstrated in…

This paper demonstrates how the transcendental number "e" may be arrived at by observing the discharge of a capacitor through a fixed resistor and then modelling the system using a simple step-wise procedure. The experimental phase makes use of the Arduino microcontroller, while simple modelling of the system is carried out by means of…

A quantitative experiment where we measure the acceleration of spheres of radius "R" rolling on an inclined U-shaped profile of width "2D" is presented. For a given inclination, we examine the behaviour of four solid spheres having different diameters; in contrast to what is usually assumed to be the case, the experimental…

In order to increase understanding of the cochlea and to illustrate its connection to basic physics, a functional model was developed. It was found to be useful in exploring the basic dynamics of the basilar membrane and its role in the frequency mapping of the cochlea.