Too often, students in introductory courses are left with the impression that Einstein's special theory of relativity comes into play only when the relative speed of two objects is an appreciable fraction of the speed of light ("c"). In fact, relativistic length contraction, along with Coulomb's law, accounts quantitatively for the force on a…

Did you know that some strong little cylindrical magnets available in local hardware stores can have an effective circumferential current of 2500 A? This intriguing information can be obtained by hanging a pair of magnets at the center of a coil, as shown in Fig. 1, and measuring the oscillation frequency as a function of coil current.

Electric Motorboat Drag Racing is a culminating high school physics project designed to apply and bring to life many content standards for physics. Students need to be given several weeks at home to design and build their model-sized electric motorboats for the 5-meter drag racing competition down rain gutters. In the process, they are discussing…

Presents a simple activity to determine the layout of the magnetic poles in a flat rubber or plastic refrigerator magnet. (JRH)

Explains how to use magnets to demonstrate the electron flow mechanism of a chemical reaction. (YDS)

Investigates the behavior of a bar magnet with a steel ball bearing on one pole as it approaches another bar magnet. Maps the problem onto electrostatics and explains observations based on the behavior of point charges near an isolated, uncharged sphere. Offers a simple demonstration of the method of images in electrostatics. (Author/NB)

The physical analysis of a uniformly accelerating point charge provides a rich problem to explore in advanced courses in electrodynamics and relativity since it brings together fundamental concepts in relation to electromagnetic radiation, Einstein's equivalence principle and the inertial mass of field energy in ways that reveal subtleties in each…

Presents an activity for students to construct their own two-cup balances. Suggests some alternatives for rejuvenating weak bar magnets. Describes how to remove burnt carbon deposits from glass vessels. (NB)

Presents a science activity on collecting micrometeorites from rainwater using magnets. Includes procedural information. (YDS)

Outlined is a simple design for a working wave-powered electrical generator based on one made on the BBC "Rough Science" TV series. The design has been kept deliberately simple to facilitate rapid pupil/student involvement and most importantly so that there is much scope for their own ingenuity and ideas. The generator works on the principle of…

In 2000, Oil City Elementary School faced collapsing enrollment, a high-risk student population, and a reputation as the place for kids who were not smart enough to attend the nearby academic magnet. The school was slated for closure. But the school had a history of connection to Oil City, a town of 1,500 in western Louisiana, and school staff…

Explains magneto-optical effects and describes techniques which may be used, in conjunction with certain materials, to reveal domain structures. In addition, simple experiments are described which enable domains to be observed under various conditions of applied fields. (Author/GA)

Short articles describe the construction and use of a probe for measuring magnetic fields, the determination of the speed of electromagnetic transmission by utilizing standard time signals relayed from an orbiting satellite, and an apparent paradox in the theory of electron deflection in cathode ray tubes. (AL)