Bulbs are considered to be very inefficient sources of light. Bulbs give light and heat. As we use them for a long time, especially in winter, a large part of the heat produced by bulbs lowers the power consumption of the heating system. In this paper the problem of the real efficiency of a bulb is solved when both the lighting and heating effects…

Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

The dynamics of some common sports, such as race walking, running, cycling, jumping, and throwing, are presented. Rough estimates of the relevant physical quantities required for these individual sports are discussed. General mathematical formulas are derived which can be used for judging the performance of any athlete. (Author/KR)

Suggests a means for narrowing the gap between the technological-school student's (twelfth-grader) mastery of pure mathematical principles and ability to apply it to electronics. Discusses factors for and against teaching applications, cooperation between mathematics and electronics teachers, test procedures, results, and analysis of findings. (YP)