We consider the operation of the hypothetical mechanical vehicle driven by an engine powered by small rockets introduced by P D Hanstead in the inaugural volume of this journal. Hanstead arrived at three contradictory conclusions regarding the change in velocity should some of the rockets malfunction at a particular time. This thought experiment…

The physics' subject aims to provide the student with a broad understanding of the physical phenomena that occur around them every day and introduce them to the scientific search. The use of experiments in the teaching of the subject contributes to the understanding of these phenomena, the development of skills and critical thinking and has many…

In a traditional teaching approach, a physics course begins with mechanics, and generally the braking effect due to magnetic interactions is not mentioned among the various types of friction presented (static, sliding, rolling) because students will discover magnetism only in later chapters. In our didactic experience this traditional choice is…

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…

The refractive index (RI) is probably the single most important parameter in optical systems. Chromatic dispersion, on the other hand, indicates how the RI depends on the wavelength and is central in, e.g., optical communication systems. Chromatic dispersion also plays an important role when teaching optics due to the captivating natural…

The wave nature of light has been widely demonstrated in a double-slit experiment, which has played a special role in physics teaching. When monochromatic light passes through the double-slit sheet, the diffraction and interference fringes can be observed in the far-field regime. The interference of light causes the beams passing through the two…

Measurements and calculations are presented showing how the trajectory of an object sliding across an inclined plane varies with the launch and incline angles. The trajectory depends on the magnitude and direction of the sliding friction force. The experiment is easy to set up, can be analysed using a video camera, and would be suitable for a…

So many fundamental physics problems involve rigid body rotation that mastery of the subject is essential to many science and engineering undergraduate degrees. Rigid body rotation is typically taught in introductory mechanics courses and while students are generally comfortable with the corresponding kinematic equations, torques and moments of…

A standard problem for physics students is to calculate or measure the acceleration of an object down an inclined plane. Additional information can be obtained by measuring the angular acceleration as well as the linear acceleration. An experiment is described where a billiard ball was filmed as it rolled down an inclined plane at different…

The Crookes radiometer (also known as a light mill) is a fascinating sunlight-powered device, in which a set of vanes is placed inside a glass bulb within which a partial vacuum has been pulled. The vanes then rotate when sunlight shines on the bulb. The reason for the turning of the vanes was subject to intense debate and many students still have…

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…

For many years, Atwood's machine has been used to demonstrate, illustrate, or verify Newton's laws in introductory physics courses. It consists of two objects of different mass that are fastened to the ends of a string that hangs over a pulley. In an idealized situation, one assumes that pulley friction, the string's mass, and changes in the…

We describe here a low-cost experiment for introductory physics students where they compare the physical properties of aluminum and steel by means of cantilever oscillations. This, in turn, allows the students to improve their physical intuition about these materials. Further, the students can apply their physics and mathematics knowledge and…

In this paper, a very simple and low-cost setup design is described for the Seebeck coefficient measurement of the disc and rod-shaped specimens. The setup has been tested for its reliable working by measuring the Seebeck coefficients of standard samples; measured values match with the literature. The setup can be built with commonly available raw…

As intriguing optical phenomena that occur in nature, mirages are widely known and often mentioned in physics classes when introducing the basics of optics. In the atmosphere, a mirage occurs under the condition of vertical variations in air density, which are usually caused by a temperature gradient. The light rays are continuously refracted and…