Published in Physics Education
An electric charge located outside a closed metal box does not produce an electric field inside the box. On the other hand, an electric charge located inside the box can generate an electric field outside the box. A charge inside the box can therefore exert a force on a charge outside the box, but not vice-versa, in apparent contradiction of Newton...
Published in Physics Education
Coloured marker pens come with different properties according to their uses. This question relates to how these properties are affected by water.
Published in Physics Education
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 furthe...
Published in Physics Education
If an empty coffee cup is spun on a horizontal surface about a vertical axis in an anti-clockwise direction, then the whole cup rotates slowly backwards, in a clockwise direction, about a vertical axis located outside the cup. Clues to this curious behaviour are presented by comparing it with other spinning objects.
Published in Physics Education
The first of the two postulates of relativity states that the laws of physics are the same in all inertial reference frames. Often it is assumed that the postulates are mainly concerned with objects moving at a significant fraction of the speed of light. However, the postulates are applicable at all speeds from a snail to a photon. To practically d...
Published in Physics Education
The voltage drop or potential difference across a resistor is easily measured with a voltmeter. However, if the loop formed by the resistor, the connecting leads, and the voltmeter surrounds a changing magnetic field then the measured voltage drop will be different. This result can lead to a paradox when using Faraday’s law.
Published in Physics Education
Three new physics teachers graduating from a university provider of initial teacher education in England were paired with a recently retired physics subject specialist teacher in order to provide informal mentoring during their first year of teaching. The aim of this was to explore if a mentoring intervention of this kind could support teacher know...
Published in Physics Education
In free fall objects seem to behave as if the physical laws of gravity have been suspended. Here are some experiments which demonstrate the phenomenon, and test the imagination.
Published in Physics Education
A question on the forces in a spring balance when different loads are apllied and the balance is also stretched with an elastic band.
Published in Physics Education
The purpose of this publication is to present a novel approach to the demonstration of the Dzhanibekov effect. The main idea of our version is to use a lightweight spinning top of a spherical external form but distinct principal moments of inertia floating in the upward flow of air. As a result, the Dzhanibekov effect can be easily demonstrated any...
