While the three laws of conservation of energy, momentum, and angular momentum are all mentioned in introductory textbooks, there are few experiments through which students can investigate the conservation of angular momentum. Most experiments consist of collisions between rotating disks, in which one disk is dropped on another, or in which the…

Experiments that measure the speed of sound in air are common in high schools and colleges. In the Kundt's tube experiment, a horizontal air column is adjusted until a resonance mode is achieved for a specific frequency of sound. When this happens, the cork dust in the tube is disturbed at the displacement antinode regions. The location of the…

The forgotten history of de Broglie waves as themselves artifacts of a Lorentz transform, not physical lengths and frequencies to be transformed, causes confusion for students and others. In this paper the de Broglie wavelength is derived and dependence of de Broglie frequency on velocity explained in terms of Einstein synchronized reference frame…

This paper describes three methods of measuring the coefficient of restitution (CoR) for two different types of ball-on-ball collision. The first collision type (for which two different CoR measurement procedures are described) is a static, hanging steel ball forming part of a Newton's cradle arrangement, which is then hit by its adjacent…

Image modelling is a recent technique in physics education that includes digital tools for image treatment and analysis, such as digital stroboscopic photography (DSP) and video analysis software. It is commonly used to analyse the motion of objects. In this work we show how to determine the position of the centre of mass (CM) of objects with…

Laboratory work in physics has traditionally focused on the verification of facts, theories and laws. In contrast, this article describes how laboratory tasks can be used to promote students understanding about the nature of science and scientific inquiry. In the project reported here, students learn about measurement uncertainties and a…

There are many lab exercises for upper-level school students and freshman undergraduates to measure the value of the local acceleration due to gravity ("g") near Earth's surface. In these exercises, the value of "g" is usually taken to be constant. The approach is often based on measuring the period of a pendulum that is…

According to the Newtonian formula for a simple pendulum, the period of a pendulum is inversely proportional to the square root of "g", the gravitational field strength. Einstein's theory of general relativity leads to the result that time slows down where gravity is intense. The two claims look contradictory and can muddle student and…

A simple setup is designed to investigate a "time-of-flight" measurement of the speed of sound in water. This experiment only requires low cost components and is also very simple to understand by students. It could be easily used as a demonstration experiment.

A very old and well-known magical trick is the so-called tablecloth pull. A table is covered with a tablecloth, on top of which are certain objects. The task is to remove the tablecloth while the objects--which must not be touched--stay on top of the table. This article describes the physics behind the experiment, and presents examples recorded…

This paper begins with an early measurement of the speed of sound in water. A historical overview of the consequent development of SONAR and medical imaging is given. A method of measuring the speed suitable for demonstration to year 10 students is described in detail, and an explanation of its systematic error examined.

Undergraduate physics laboratories seldom have experiments that measure the Coriolis acceleration. This has traditionally been the case owing to the inherent complexities of making such measurements. Articles on the experimental determination of the Coriolis acceleration are few and far between in the physics literature. However, because modern…

The accurate measurement of speed of light is of great importance in understanding various concepts in Physics in particular and science in general. In Physics we come across various concepts and applications in which high degree of accuracy of speed of light becomes important. In this article we discuss the various attempts made to determine the…

The measurement of the force acting between two parallel, current-carrying wires is known as Ampère's experiment. A mechanical balance was historically employed to measure that force. We report a simple experiment based on an electronic precision balance that is useful in clearly showing students the existence of this interaction and how to…

This paper aims at contributing to a better understanding of the motion of spherical particles in viscous fluids. The classical problem of spheres falling through viscous fluids for small Reynolds numbers was solved taking into account the effects of added mass. The analytical solution for the motion of a falling sphere, from the beginning to the…