摘要:

The availability of powerful microcomputers with graphics capabilities expands the range of numerical procedures that can be employed for undergraduate use. The use of simple software packages for the evaluation of multidimensional WKB approximate eigenvalues is discussed. Introductory courses in quantum mechanics rarely make use of semiclassical theories, such as WKB, to relate quantum mechanics to classical mechanics. This relationship can be helpful for the student’s understanding of quantum mechanics, and a computer experiment can provide a useful avenue for making the concepts concrete. The major components of the approach involve the use of a package for the integration of differential equations, to treat the classical equations of motion, and a computer‐aided design package to determine the phase integral areas. The codes are not expensive, and all exploit the graphical capabilities of microcomputers, which are critical for visualizing the relationship between classical and quantum ideas.

ISSN:0002-9505    

DOI:10.1119/1.16595

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Shift operators are derived forsstates of the Hulthén potential. These operators are used to obtain energy eigenvalues and normalized coordinate‐space wave functions for boundsstates. The condition for the existence of these states is deduced from the Hellmann–Feynman theorem, and this theorem together with the hypervirial theorem are used to calculate certain expectation values.

ISSN:0002-9505    

DOI:10.1119/1.16596

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

When introducing oscillations, beginning physics courses typically only discuss the harmonic oscillator. This is natural, but this exclusive focus may disguise its special features (e.g., frequency‐amplitude independence). Using an air track, our students investigate oscillations experimentally and match experimental data with theoretical curves. An additional theoretical choice, along with the damped harmonic oscillator, is the solution for the nonharmonic force lawF=−F0 sgn(x)−γv. When there is no damping (γ=0) there is a difference of less than 0.06 between the nonharmonic and the harmonic oscillator curves if both have unit amplitude and the same frequency and phase. Still, the accuracy of the data allows discrimination between these models. However, the difference shows up most clearly when damping is present since then the period of the nonharmonic oscillator changes with the amplitude and curves that start in phase become out of phase. A simple approximate solution for this damped nonharmonic oscillator has been obtained.

ISSN:0002-9505    

DOI:10.1119/1.16597

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

A simple program is presented for producing zone plates on laser printers, and some of its results and possible applications are discussed.

ISSN:0002-9505    

DOI:10.1119/1.16598

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The Lienard–Wiechert formalism is applied to the problem of a charged particle traversing a one‐dimensional periodic potential. An expansion is made in terms of the ratio of the amplitude of the periodic potential to the incident energy. It is found that a discrete radiation spectrum is obtained to lowest order of the expansion.

ISSN:0002-9505    

DOI:10.1119/1.16599

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

The great prestige of the Nobel Prizes has come virtually to define physics in the public mind. An examination of the nominations and the selections in the first 37 years of Nobel awards shows that those in charge of the selections went through a process of development as they refined their conceptions of the kind of work appropriate to be rewarded. Analyses are presented of the 1800 nominations made by 448 nominators for 213 scientists, of whom 44 received physics prizes between 1901 and 1937, 10 more who were awarded Nobel Prizes in physics after 1937, and 12 in chemistry, although nominated also in physics.

ISSN:0002-9505    

DOI:10.1119/1.16600

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16834

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

摘要:

Thr reflection of sound waves from buildings on the University of California, Berkley campus is studied. (AIP)

ISSN:0002-9505    

DOI:10.1119/1.16601

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16602

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.16603

出版商:American Association of Physics Teachers    

年代:1991

数据来源: AIP