A light flasher was developed for use with the open-shutter photography technique in elementary-mechanics experiments. Details are given of its design and construction. Five experiments, for the elementary mechanics laboratory, which use flasher units are described. (DT)

Expressions to describe fringe contours in the region of interference of two coherent beams are derived for three combinations of plane and spherical wave geometrics. (Author/SL)

Presents a simple means of visualizing and generating families of Rayleigh hysteresis loops. (SL)

Describes a pedagogical method for measuring the coefficient of restitution for collisions between a bouncing ball and a horizontal surface by measuring the sound made by the bouncing ball. (MLH)

Provides a definition of electric energy density by drawing a circuit analog. (SL)

The observations that would be made by a uniformly accelerated observer, including the observer's event horizon, the variation of clock rates with position, and the effects of following a freely falling object are considered in detail. (SL)

Discusses Hertz vector potentials and demonstrates their application to the calculation of electric and magnetic dipole radiation and to the propagation modes of a rectangular waveguide. (Author/SL)

Presents a method for describing the electromagnetic field within a wave guide which permits the application of the formalism of quantum mechanics. (SL)

Presents methods for estimating running speed, length of a broad-jump, height of a pole vault, and time to run up a flight of steps as examples of elementary numerical mechanics. (SL)

Presents a new application of the WKB approximation to the hadronic atom elementary enough for undergraduate quantum mechanics students. (SL)

Describes a concrete model for teaching the concepts of reflection and refraction without the use of formal mathematics. The model has been tested in five sections of a physics course for nonscience majors at Towson State University, Baltimore, Maryland. (HM)

Suggests the use of a coordinate-free rotation operator for the teaching of rotations in Euclidean three space because of its twofold didactic advantage. Illustrates the potentialities of the coordinate-free rotation operator approach by a number of examples. (Author/GA)