摘要:

The relativistically correct equations of motion for a ’’free’’ electron in a plane electromagnetic wave are written down including radiation damping. Iteration is used to obtain first, the exact solutions neglecting radiation damping, then, corrected solutions including radiation damping. It is seen that without radiation damping the electron will not experience forward acceleration caused by ’’radiation pressure.’’ With radiation damping included, the (constant) acceleration caused by radiation pressure is clearly seen. The effective cross section for the transfer of momentum to the electron is just the Thompson cross section. A ’’Compton formula’’ is obtained that is seen to have the same angular dependence as the ordinary Compton formula. The significance of the Compton formula is then perceived not to lie in its angular dependence, but in its wave independence.

ISSN:0002-9505    

DOI:10.1119/1.10775

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The Personalized System of Instruction (PSI) is probably the most widely used recent innovation in physics teaching. While much has been written about its ’’educational effectiveness,’’ little is known about the survival of PSI courses after they are introduced. In a study of particular interest to the readers of theAmericanJournalofPhysics, we examined the survival of all 12 PSI courses reported in theJournalthrough 1975. Seven of the 12 were still being taught. The experience of those who introduced these courses is used to provide background for teachers thinking of adopting the method and to give perspective on the survival of PSI as an innovation.

ISSN:0002-9505    

DOI:10.1119/1.10776

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

Using a pedagogical model introduced by Dresden and Feiock, the quantum mechanical version of the Kac ring model, the following studies are illustrated: (a) solution of the Liouville equation using projection techniques; (b) analysis of the difference between the linear and nonlinear theories; and (c) existence of a kinetic description, with the solution of the Pauli master equation for this example.

ISSN:0002-9505    

DOI:10.1119/1.10777

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The Heinsenberg theory of ferromagnetism has been treated by many types of approximations; one of the more successful is known as constant coupling. The literature contains several different ways of arriving at results like those of the constant‐coupling approximaion, but proofs that they are indeed equivalent are lacking in some cases. It is shown that two of these methods are equivalent for spin 1/2 and explicitly demonstrated that both yield exactly the constant‐coupling results, though simpler in use and concept than the latter. Finally, it is shown that one of the two methods yields the same Curie temperatures as constant coupling for all spin.

ISSN:0002-9505    

DOI:10.1119/1.10778

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

Two parallel explanations of homodyne Doppler velocimetry are discussed as well as its application in an undergraduate experiment. This phenomenon is applied in the measurement of the constant acceleration of coupled masses utilizing the microwave region of the electromagnetic spectrum. One mass is an air car with radar reflector and is coupled by a pulley system to the other, a drop weight. AJP

ISSN:0002-9505    

DOI:10.1119/1.11033

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

For the past six years, freshman nonscience students at The University of Michigan–Dearborn have been introduced to the sciences through a unique, one‐year, integrated, interdisciplinary, team‐taught course, ’’Matter, Energy and Life.’’ The principal objective of the course is to develop the scientific literacy of the students and to prepare them to deal with the scientific problems they will face as citizens. Physics principles represent an essential component of the course, and are integrated into both lectures and laboratory exercises. Experience with this approach, and both peer and student evaluations, have shown its effectiveness in generating student interest in the sciences.

ISSN:0002-9505    

DOI:10.1119/1.11034

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The peculiar tendency of the laboratory spring–mass oscillator to swing sideways is analyzed. The physical explanation for this motion involves a decay mode called a ’’parametric instability’’; the ’’inverse parametric instability’’ is also intimately involved. The theory of a completely reversible cyclic process is developed and a method of predicting the maximum swinging amplitude is presented. This inherently nonlinear phenomenon illustrates the important role played by instabilities in transferring energy from one degree of freedom of a system to another. An analogy is drawn between the swinging of the oscillator and the interaction among several waves propagating in a nonlinear medium.

ISSN:0002-9505    

DOI:10.1119/1.11035

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The motion of a particle in a noncentral potential is discussed using the action‐angle formalism. The results are verified in the small oscillation approximation.

ISSN:0002-9505    

DOI:10.1119/1.11036

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

The WKB method is applied to the calculation of strong interaction‐induced level widths and shifts of hadronic atoms. The calculation, while elementary enough for undergraduate quantum mechanics students, gives a good account of kaonic and antiprotonic atom data.

ISSN:0002-9505    

DOI:10.1119/1.11037

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP

摘要:

This paper describes a completely arithmetic development of Newtonian dynamics in which all the classical conservation laws are valid. The equations are already in a form amenable to high‐speed digital computation. Related particle‐type models are then described for highly nonlinear dynamical phenomena, and computer examples are given to illustrate the ease with which they can be analyzed.

ISSN:0002-9505    

DOI:10.1119/1.11038

出版商:American Association of Physics Teachers    

年代:1977

数据来源: AIP