Presents a simpler derivation for centripetal acceleration for use when students are first introduced to the topic. (PR)

Introduces the method of ray tracing to analyze the refraction or reflection of real or virtual images from multiple optical devices. Discusses ray-tracing techniques for locating images using convex and concave lenses or mirrors. (MDH)

An analogy, which has been drawn between black hole physics and thermodynamics, is mathematically broadened in this article. Equations similar to the standard partial differential relations of thermodynamics are found for black holes. The results can be used to supplement an undergraduate thermodynamics course. (Author/SK)

While it is most often the case that an understanding of physics can simplify mathematical calculations, occasionally mathematical precision leads directly to a better physical understanding of a situation. Presents an example of a mechanics problem in which careful mathematical derivation can lead directly to a deeper physical understanding of…

Starting from the energy and degeneracy of the Landau levels of a free-electron gas in a magnetic field, the nonoscillatory term of the Landau diamagnetism is derived for T=O, using elementary algebra only. (Author/JN)

Presented is a derivation for the matrix representation of an arbitrary boost, a Lorentz transformation without rotation, suitable for undergraduate students with modest backgrounds in mathematics and relativity. The derivation uses standard vector and matrix techniques along with the well-known form for a special Lorentz transformation. (BT)

Using covarient harmonic oscillator formalism as an illustrative example, a method is proposed for illustrating the difference between the Poincare (inhomogeneous Lorentz) and homogeneous Lorentz groups. (BT)

Describes a theoretical development to explain the shadow patterns of an object exposed to an extended light source while held at varying distances from a screen. The theoretical model is found to be accurate in comparison with experimental results. (MDH)

A common misconception among students setting up force-acceleration problems is to think of the expression "mass times acceleration" as a force itself. Presents a new formula to express the relationship between force, mass, and acceleration, and discusses its benefits. (MDH)

Introduces a new sign convention for the object and image distances involving mirrors and lenses. Proposes that the method is easier for students to understand and remember and that it helps clarify the physics concepts involved. (MDH)

Establishes a rationale for teaching population genetics to students and inservice biology teachers. Suggests strategies for introducing students to the Hardy-Weinberg principle. (MDH)

Presents simple experiments using the flow of water from bell jars that can provide an easily visualized introduction to exponential decay. (Author)

Describes problems using the Jenkins and White approach and standard diffraction theory when dealing with the topic of finite conjugate, point-source resolution and how they may be resolved using the relatively obscure Abbe's sine theorem. (JN)

Discussed is the virial theorem, which is useful in classical, quantum, and statistical mechanics. Two types of derivations of this theorem are presented and the relationship between the two is explored. (BT)

Investigates the use of mathematical representations in 3 grade-8 general science classes (n=65) that engaged in a 10-week open inquiry about the correlations between biological and physical variables in the environment. Demonstrates the use of representations as conscription devices, and illustrates how the use and understanding of inscriptions…