Introductory General Physics Research Articles

On the circular orbits of a particle sliding on the inside of a generic surface of revolution

A classical problem in introductory general physics courses is the determination of the properties of the circular orbits of a particle sliding without friction on the inside of an inverted cone. Typically, the aim is to find the speed of the orbit or other physical quantities of interest as a function of the height of the particle. Here, we generalize this problem by studying the properties of the circular orbits of a particle sliding on the inside of generic surfaces of revolution ρ(z) using basic Newtonian mechanics. Given the surface ρ(z), we obtain equations to calculate several physical quantities of interest (namely the speed v, the angular velocity ω, the total mechanical energy E and the angular momentum L) of the circular orbits inside the surface. Conversely, we also study the inverse problem: the determination of surfaces in which any of the physical quantities of interest (v, ω, E or L) associated with the orbits presents a desired functional dependence on the height of the particle's orbit. As an example, we find the surfaces in which these quantities are constant in all the circular orbits. Finally, we study such surfaces using analytical mechanics.

Electrons as field quanta: A better way to teach quantum physics in introductory general physics courses

I propose a conceptual change in the way we teach nonrelativistic quantum physics in introductory survey courses and general modern physics courses. Traditional instruction treats radiation as a quantized electromagnetic wave that, because it is quantized, is observable only as discrete field quanta, while treating matter as particles that are accompanied by a wave function. In other words, traditional instruction views radiation as fundamentally a field phenomenon, and matter as fundamentally a particle phenomenon. But quantum field theory has a more unified view, according to which both radiation and matter are continuous fields while both photons and material particles are quanta of these fields. The quantum field theory view of radiation and matter clarifies particle identity issues, dispels students’ Newtonian misconceptions about matter, arguably resolves the wave-particle paradox, is the accepted view of contemporary physics, and might be the simplest and most effective teaching approach for all students. I propose that we make this field-theory viewpoint the conceptual basis for teaching non-relativistic quantum physics.

Polymer Physics in an Introductory General Physics Course

Do all solids expand upon heating? To most people's surprise, there is a class of rather common solids, namely rubbery elastic polymers, capable of contracting upon heating1,2 while staying in the same solid phase. This seems contradictory to common sense and the physical theories of thermal behavior of ordinary solids. The physical behavior of elastic polymers continues to amaze physics and chemistry students as well as many scientists, despite the fact that it was experimentally detected in natural rubbers two centuries ago. For the following 125 years this phenomenon remained unexplained. An explanation was finally found only in the 1930s when the new science of “polymer physics” emerged. The goal of this paper is to demonstrate that some elements of polymer physics can be useful in teaching introductory general physics, especially in discussing the thermal properties of solids and for introducing the concept of entropy. Initially, several simple demo/lab experiments manifesting the extraordinary thermal properties of rubbers will be discussed. A brief description of the search for an explanation of the physics underlying this behavior will follow. The discussion will include the macromolecular hypothesis of Staudinger,3 the notion of a conformational state of a macromolecule, and the idea of statistical probabilities for the end-to-end macromolecular distances.1,2,4 The latter leads directly to an explanation of the emergence of the entropic force that is responsible for contraction upon heating. These notions are shown to be easily employable for introducing the idea of entropy to a beginner.

Initial understanding of vector concepts among students in introductory physics courses

We report the results of an investigation into physics students’ understanding of vector addition, magnitude, and direction for problems presented in graphical form. A seven-item quiz, including free-response problems, was administered in all introductory general physics courses during the 2000/2001 academic year at Iowa State. Responses were obtained from 2031 students during the first week of class. We found that more than one quarter of students beginning their second semester of study in the calculus-based physics course, and more than half of those beginning the second semester of the algebra-based sequence, were unable to carry out two-dimensional vector addition. Although the total scores on the seven-item quiz were somewhat better for students in their second semester of physics in comparison to students in their first semester, many students retained significant conceptual difficulties regarding vector methods that are heavily employed throughout the physics curriculum.

CAPA—An integrated computer-assisted personalized assignment system

A new integrated computer-assisted personalized assignment (CAPA) system that creates individual assignments for each student has been developed and found to be a powerful motivator. The CAPA system allows students to enter their answers to personalized assignments directly via networked terminals, gives immediate feedback and hints (allowing challenging questions), while providing the instructor with on-line performance information. The students are encouraged to study together which is known to be an effective learning strategy, but each must still obtain his/her own correct answers. Students are allowed to re-enter solutions to the problems before the due date without penalty, thus providing students with different skills levels the opportunity and incentive to understand the material without being judged during the learning process. The features and operation of the system are described, observations on its use in an introductory general physics class are reported, and some of the highly favorable student reactions are included.

Analog computer laboratory with biological examples

The use of biological examples in teaching applications of the analog computer is discussed. In an introductory general physics laboratory class which included biology majors, the addition of some biologically relevant analog computer problems was well received. The response indicates that such problems can be particularly useful in physics classes which include life-science students or which explore biophysics topics. Several suitable examples from mathematical ecology, enzyme kinetics, and tracer dynamics are described.

A “Medical Physics” Course Based Upon Hospital Field Experience

A new course in “medical physics” with a basic element of direct hospital field experience is described. Noncalculus, the course is designed to follow an introductory general physics or chemistry course. Intended primarily for premedical students, the course may be taken by nonscience majors interested in health studies. Eighteen hours of in-hospital time are included for each student, supplemented by laboratory work in the physics department, including radiation dosimetry studies with a 2.5 meV van de Graaff accelerator using thermoluminescent dosimetry techniques that allow students to develop their interests into research projects.

An Experiment-Oriented General Physics Course

An experiment-oriented course of introductory general physics was carried out by the author and eight volunteer students at Andrews University, Berrien Springs, Michigan, during the 1963–1964 school year. This paper reports on the structure of the course and the evaluation of the approach from the vantage point of 312 years' elapsed time. The course used experiments to introduce and develop most of the topics normally covered in a course of introductory college physics. Teacher and students are generally enthusiastic about the approach and think it should be further developed.

Winans, John Gibson. Introductory general physics. Boston: Ginn and Company, 1952. 765 P. $5.75

Science EducationVolume 38, Issue 4 p. 322-322 Book Review Winans, John Gibson. Introductory general physics. Boston: Ginn and Company, 1952. 765 P. $5.75 First published: October 1954 https://doi.org/10.1002/sce.37303804102AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume38, Issue4October 1954Pages 322-322 RelatedInformation

BOOK REVIEWS

Book reviewed in this article:Introductory General Physics, by John Gibson WinansMathematics for Engineers, by Raymond W. Dull and Revised and Edited by Richard DullBuilding Mathematical Concepts in the Elementary School, by Peter Lincoln SpencerThe Arithmetic of Better Business, By Frank J. McMackin, John A. Marsh, and Charles E. BatenSun, Moon and Planets, by Roy K. MarshallYour Telephone and How It Works, by Herman and Nina SchneiderMathematics: A Second Course, by Myron F. Rosskopf