Ion transport, involving the diffusion and migration of ions within the electrolyte, stands as a fundamental concept in electrochemistry and serves as the driving force for electrochemical reactions. Electric double layers are critical in the fields of electrochemical energy storage and chemical conversion, constituting a central focus of…

What happens when a perfectly elastic ball collides with a completely inelastic ball? It is shown that the outcome depends on the stiffness of each ball. A standard textbook problem in mechanics is to calculate the outcome of a head-on collision between two balls using conservation of momentum and kinetic energy. It is easily shown that the…

A loop-the-loop experiment is described to show how sliding friction affects motion of the ball. Conservation of energy can be used to explain the basic physics, but significant energy loss is observed in practice and expands the usefulness of this apparatus as a teaching tool.

A loop-the-loop experiment usually involves a ball rolling around a vertical loop. A different version of the experiment is described where a nut was allowed to slide around a vertical loop. In both experiments there is a large decrease in kinetic energy when the ball or the nut first enters the loop.

A collision of one object with two or more objects is relatively complicated in general, but a simple example is provided by Newton's cradle since all the objects are identical and in line. In the present paper, an experiment is described where a heavy mallet collides head-on with two billiard balls. The two conservation equations indicate that…

In one of the Faraday's experiments an electric current is induced in a conducting loop when a magnet in front of it moves towards or away from the loop. While the direction of circulation of the electric current in the loop has only two options, it depends on three experimental conditions that generate eight cases. Even though the Faraday law or…

An electric motor converts electrical energy into mechanical work and an electric generator converts mechanical work into electrical energy. The symmetry between the motor and generator naturally leads to questions about creating a perpetual motion machine. The allure of this question has inspired textbook problems, physics education articles, and…

Electrification by rubbing different materials is a well-known phenomenon with a history that began more than five centuries B.C. ago. However, simple experiments can lead to contradictory or inconsistent results, and the history of this phenomena is plagued with non-intuitive results. For example, triboelectric charging by rubbing identical…

In this work, a simple rocking pendulum, in a circular arc shape, is presented. The idea is to put a rigid arc on a clean flat surface of glass and leave it to oscillate under the effect of a little impulse. Then, the periodic time of this arc pendulum's motion is experimentally determined. The mathematical analysis of the arc's motion is derived…

The coefficient of restitution (COR) for a collision is usually a number between 0 and 1 depending on whether the collision is completely inelastic, or perfectly elastic or something in between. That is the usual situation for colliding spheres or a ball dropped on a horizontal surface. A different situation arises when a bat collides with a ball.…

In the light of own measurements on a Faraday generator, the well-known theories concerning Unipolar Induction and the Faraday paradox seem to be problematic. On the other hand, all results obtained, and all other processes described as a paradox in connection with the Faraday generator can be explained without contradiction based on the theory of…

A previous journal article established that a hanging Slinky's restoring force is due only to the coils between the support and the Slinky's center of mass (hereafter COM). Correspondingly, it is expected the Slinky's elastic potential energy (hereafter EPE) is associated with only those coils; however, there is no confirming experimental…

In this article we present a simple experimental set-up to determine the band gap of germanium and silicon using the "ExpEYES-17" kit. The experiment is based on the temperature dependence of the reverse current through germanium and silicon diodes at different temperatures. The experimental values are found to agree well with accepted…

We present a simple and affordable method for making a surface electrodynamic trap for microparticles. The principles of electrodynamic trapping of charged particles are discussed and step-by-step instructions on how to make a surface trap are given. In addition to the electrodynamic trap implementation and operation process, options for its…

We present a thermodynamics experiment suitable for first year undergraduate students employing Stirling Engines to create a demonstration of energy transformation and to measure the mechanical efficiency of such engines. Using an inexpensive transparent chambered Stirling Engine, students can connect concepts such as the theoretical…