Described are the components for a high-fidelity sound-reproducing system which focuses on various program sources, the amplifier, and loudspeakers. Discussed in detail are amplifier power and distortion, air suspension, loudspeaker baffles and enclosures, bass-reflex enclosure, drone cones, rear horn and acoustic labyrinth enclosures, horn…

This article describes an introductory physics laboratory program which teaches three skills: (1) the ability to make estimates and order-of-magnitude calculations, and to use these to check experimental work, (2) the ability to use qualitative and quantitative statistics, and (3) the ability to describe an experiment in one's own words.…

This article is a preview of the book, "Physics News in 1980." Five research areas are reviewed: high energy particle accelerators, fusion reactors, solar cells, astrophysics, and gauge theories. (Author/DS)

Considers several cosmological facts that relate to formulating accurate models about the universe, including the red shift, the unbounded universe, and the curvature of space. (CS)

Provides examples of several ways that humor may be used in the physics classroom. Included are the use of cartoons, puns, visual puns, unusual units of measurement, scientific errors which have amusing consequences, posters, and amusing problem sets. (CS)

Provides a brief history of electrets and describes how they can be made in a small laboratory. Also summarizes the uses of electrets and suggests projects and experiments with them. (CS)

Provides an explanation for the apparent emission of x-rays from video display terminals. (CS)

Presents a demonstration of wave behavior, and experiments of (1) the determination of the mechanical equivalent of heat, and (2) a "discovery" investigation based on the maximum-span staircase. (CS)

Discusses errors and misleading statements found in discussing the meaning of the minus sign in treating the topics of the conservation laws of energy, momentum, and angular momentum. (CS)

Summarizes the advantages in using the Daedalon Air Table, which supplies compressed air to the pucks instead of the table surface itself. Describes methods for constructing an electronic null detector using a Weston type galvanometer and an integrated circuit operational amplifier. Also describes a redesigned and improved sound-level meter. (CS)

Lists titles of articles, notes, and letters together with the names of their authors for Volume 18 of the "Physics Teacher." Classification is based upon an analysis of the contents rather than upon the titles alone. (CS)

Lists alphabetically by author the articles, notes and letters published in Volume 18 of the "Physics Teacher." (CS)

Traces the events leading to the creation of the International Bureau of Weights and Measures (BIPM). Discusses how the units have been represented by their standards, and investigates how the original metric system evolved into the International System of Units (SI), focusing on the meter, second, kilogram, and electrical units. (SK)

Presents eight examples from two elementary school science textbook series of misleading suggestions related to what students should observe during science lessons. Levels and page numbers are given for each example. Questions whether textbook authors have tried and analyzed the experiments they describe. (Author/SK)

Results of considering the "at rest" condition of an object with two high school physics classes suggest three instructional factors which apparently aid in the development of students' concepts of force. Includes implications for teaching and an example of a technique fostering concept development. (Author/JN)