The Enskog factor [chi] plays a central role in the theory of dense gases, quantifying how the finite size of molecules causes many physical quantities, such as the equation of state, the mean free path, and the diffusion coefficient, to deviate from those of an ideal gas. We suggest an intuitive but rigorous derivation of this fact by showing how…

The refraction of a light ray by a homogeneous, isotropic and non-dispersive transparent material half-space in uniform rectilinear motion is investigated theoretically. The approach is an amalgamation of the original Fermat's principle and the fact that an isotropic optical medium at rest becomes optically anisotropic in a frame where the medium…

In this work, the oscillations of a homogeneous string fixed at both ends, and loaded with a finite number of masses, are studied. Through a simple device, the cases with one and two concentrated masses are analysed in detail. The normal modes are observed and the corresponding frequencies are recorded. The experimental results and the solutions…

Faraday's and Furry's formulae for the electromagnetic momentum of static charge distributions combined with steady electric current distributions are generalized in order to obtain full agreement with Poynting's formula in the case where all fields are of class C[superscript 1], i.e., continuous and continuously differentiable, and the…

This note considers a family of piece-wise linear functions that can be used in the classroom to illustrate various concepts involved in iteration theory such as periodicity. These functions require minimal background on the part of the student. (Contains 2 figures.)

Describing the world in terms of energy is necessarily quantitative: one must be able to do the sums for the description to gain a purchase. Whilst teaching younger children (say 11-14 years old) the full quantitative description is not available and this has made the introductory teaching of energy a contentious area. By focusing on…

Numerous connections exist between climate science and topics normally covered in physics and physical science courses. For instance, lessons on heat and light can be used to introduce basic climate science, and the study of electric circuits provides a context for studying the relationship between electricity consumption and carbon pollution. To…

This paper aims to supplement the scant literature on the history of ideas about the nature of sound. It presents how notions about the production and propagation of sound developed from antiquity up to the 17th century, i.e. from the time of Pythagoras to the time of Sauveur. It will highlight and examine the principles of sound that were…

Technology-Enabled Active Learning (TEAL) is a pedagogical innovation established in a technology-enhanced multimedia studio, emphasizing constructivist-oriented teaching and learning. In Taiwan, an increasing number of schools are adopting the TEAL notion to deliver courses. This study examines the impact of TEAL on both student performance and…

This book is a collection of classroom demonstrations in physics designed to present basic scientific ideas on a concrete level. The topics covered include: physical change and properties of matter; energy waves and energy forms; absorption of heat; radiant energy; vacuum bottles; kinetic molecular theory; states of matter; pressure of air; work…

Models occupy the content core of physics, and modeling is a major process for constructing and employing physics knowledge. A model is characterized by its domain, composition, structure, behavior, and organization. Problem solving is a schematic modeling process consisting of model selection, construction, validation, analysis, and deployment. A…

Describes construction of an exhibit which uses the acceleration of an elevator to distinguish mass and weight. (CP)

Discusses some unitary transformations of the Dirac equation and methods of dealing with free massless electrons and Maxwell's equations. (CP)

In this paper a formalism is developed that enables one to write by inspection the matrix which represents the transformation between two coordinate systems, one of which is rotated about an arbitrary axis. (Author/CP)

Describes a four page paper written by S. Bose who helped found quantum statistics. The consequences of the paper to modern physics are presented. Contrasted are the scientific relationships of Einstein, Dirac, and Bose. (GH)