摘要:

A semi-quantitative presentation of gravitational collapse into white dwarfs, neutron stars, and black holes is given at the level of the introductory college physics course. Final radii, star composition, and critical masses are estimated using basic principles from the introductory course.

ISSN:0002-9505    

DOI:10.1119/1.1987503

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

The one-dimensional periodic-potential problem is solved using the Laplace transform method. This method allows an easy generalization of the Kronig-Penney model so that it is applied to solve far more complex one-dimensional periodic structure.

ISSN:0002-9505    

DOI:10.1119/1.1987504

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

Equations of motion are generated for a classical particle in a Riemannian space with arbitrary metric, moving in a velocity-independent potential, and acted upon by a linear frictional force. Only the Lagrangian formalism is used, but the Lagrangian function is not of standard form. As an example, a satellite moving in a linearly-viscous atmosphere is considered. This approach yields immediately a constant of the motion which is a generalization of the usual angular momentum. A particle moving on the viscous surface of a sphere is also discussed. Finally, the equation of motion for a particle moving in one dimension subject to a frictional force quadratic in the velocity is generated geometrically by choosing an appropriate nonanalytic metric.

ISSN:0002-9505    

DOI:10.1119/1.1987505

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

Numerical solutions of the Schrödinger equation for a wide variety of one-dimensional problems, as well as three-dimensional spherically symmetric problems, can be obtained by students with a small computer and a general, interactive computer program. The program is described and a typical student-computer interaction is presented. As an application, solutions to the Thomas-Fermi-Dirac central field approximation for 4f electrons at the onset of the first rare-earth series of elements are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1987506

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

This article presents a new way to introduce scattering theory. This new method is based on the use of a computer (even a small one) to calculate classical particle trajectories and then quantum mechanical phase shifts. The method is very visual and is easy to explain as well as to perform. The students gain a much better physical understanding of the scattering process than has previously been possible.

ISSN:0002-9505    

DOI:10.1119/1.1987507

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

Teaching coherent optics from an engineering viewpoint in a laboratory for undergraduate electrical engineering students has been an exciting and motivating experience. The philosophy, objectives, and experimental contents of this undergraduate laboratory offer a possible exposure for our undergraduates to modern coherent optics. We report in this paper on an undergraduate engineering laboratory in this field. The basic philosophy and objectives of the chosen experiments are briefly described. A few examples of the experiments are illustrated. An overall laboratory evaluation and concluding remarks are also given. In short, it is found from the response of the students that the laboratory is exciting, motivating, and stimulating. Generally, the students favor having this coherent optics laboratory.

ISSN:0002-9505    

DOI:10.1119/1.1987508

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

The absolute electrometer, a device used historically to determine potential difference directly by measuring the electrostatic force between the plates of a charged capacitor, forms the basis for an experiment to determine the permittivity of free space,ε0.The inherent instability of the device at high voltage is analyzed and the optimum conditions for operation are developed. The correction to the capacitance due to a discontinuity in the guard-ring-plate surface is calculated using the method of conjugate functions. The correction differs from one calculated previously.

ISSN:0002-9505    

DOI:10.1119/1.1987509

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

The steady state electrical behavior of a nerve subjected to small signals provides an example of voltage attenuation in a resistance ladder. If capacitive effects are included, the nerve is similar to a cable with capacitance but without inductance. Discussion of the steady state problem is within the scope of a noncalculus general physics course, and students going into medicine or the life sciences would benefit from such a treatment. This paper introduces physics teachers to the basic properties of a nerve axon, the networks analogous to it, and the regenerative changes in the electrical properties of the nerve membrane which accompany the propagation of the action potential. These have been known to physiologists for over twenty years but are rarely discussed in physics courses.

ISSN:0002-9505    

DOI:10.1119/1.1987510

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

An experimental approach to birefringence has been developed for the introductory physics course. The experiments enable students to explore quantitatively the relationship between birefringence (or retardation) and the colors transmitted through birefringent material between crossed polarizers. An expression for transmitted intensity is derived, and two experiments are described, one using a grating spectrometer and the other a scanning spectrophotometer.

ISSN:0002-9505    

DOI:10.1119/1.1987511

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP

摘要:

It is proven that the modified Hamilton's principle, in which both the coordinates and momenta are varied independently, can be derived from Hamilton's principle in which only the coordinates are varied independently.

ISSN:0002-9505    

DOI:10.1119/1.1987512

出版商:American Association of Physics Teachers    

年代:1973

数据来源: AIP