Describes an exhibit containing four basic demonstrations relating to center of gravity and rotational equilibrium. The demonstrations involve (1) the stack of bricks, (2) the double cone, (3) the spool roller, and (4) the platform balance. (MDH)

The equilibrium of a flexible inextensible string, or chain, in the centrifugal force field of a rotating reference frame is investigated. It is assumed that the end points are fixed on the rotation axis. The shape of the curve, the skipping rope curve or "troposkien", is given by the Jacobi elliptic function sn. (Contains 3 figures.)

Two problems in projectiles are discussed which generate interesting loci.

Energy is a critical concept in physics problem-solving, but is often a major source of confusion for students if the presentation is not carefully crafted by the instructor or the textbook. In the first three articles in this series we discussed several issues related to the teaching of energy concepts. We have saved a major single issue for this…

Fermi problems, or order of magnitude estimates, are often used in introductory physics courses. In this paper I will show that first year students studying physics at university do not arrive with the skill set to solve these problems, and they have to be actively taught how to solve them. Once they have been shown how to solve Fermi problems,…

The purpose of this book is to describe the basic mechanisms whereby pollution is transported and diffused in the atmosphere. It is designed to give practitioners an understanding of basic mechanics and physics so they may have a correct basis on which to formulate their decisions related to practical air pollution control problems. Since many…

Explains the properties and gives the derivations of Airy's functions for simple example problems on stress such as the cantilever beam and the tensional cross-bow. (GA)

Presents an application of the formulas of kinematics to the real driving situation, involving motion at constant speed and deceleration. Suggests the problem be used as an example in class, a homework assignment, or a test item. (CC)

Presents an application of fundamental principles of mechanics for an isolated system in solving problems related to rocket velocity and exhaust elements. (JRH)

This case study illustrates the sequential process of the joint and individual knowledge elaboration in a computer-supported collaborative learning (CSCL) environment. The case comprised an Internet-based physics problem-solving platform. Six Dutch secondary school students (three males, three females) participated in the three-week experiment.…

Through everyday experience people acquire knowledge about how moving objects behave. For example, if a rock is thrown up into the air, it will fall back to earth. Research has shown that people's ideas about why moving objects behave as they do are often quite inconsistent with the principles of classical mechanics. In fact, many people hold a…

Abstract. The conditions under which one can gain mechanical advantage by pulling with a force F perpendicular to a cable (or rope) that is fixed at both ends are examined. While this is a commonly discussed example in introductory physics classes, its solution in terms of fundamental properties of the cable requires one to model the elasticity of…

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 a contest in which students attempt to build a device that produces a donut-shaped air pulse that will travel the greatest distance with the most accuracy. (WRM)