ISSN:0002-9505    

DOI:10.1119/1.13738

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.4755901

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.4755903

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

This Resource Letter provides a guide to the literature on x‐ray astronomy. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of somewhat more specialized nature; and the letter A indicates rather specialized or advanced material. An asterisk (*) indicates those articles to be included in an accompanying reprint book.

ISSN:0002-9505    

DOI:10.1119/1.13916

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

The relativistic addition law for parallel velocities is derived directly from the principle of relativity and a few simple assumptions of smoothness and symmetry, without making use of the principle of the constancy of the velocity of light.

ISSN:0002-9505    

DOI:10.1119/1.13917

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

An expansion based on a finite series of nonideal axial multipoles is presented. It is suggested that it constitutes a better introduction to the teaching of the multipole expansion than the usual power series. As an application, the equivalence between a nonideal dipole and an ideal one plus an infinite set of nonideal octupoles is shown.

ISSN:0002-9505    

DOI:10.1119/1.13918

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

Using a solar cell/photodiode in conjunction with a multimeter for measuring current/voltage, the output from the solar cell or photodiode was recorded as distance from a light source was varied. For a constant power source the distance dependence of the intensity depends only on the source geometry. Three source geometries for which students can derive the theoretical distance dependence are the point source, the line source, and ring source. For the line source the intensity decreases asr−1.01±0.01compared with the theoretical behavior ofr−1.00, exactly. For the point source it decreases asr−2.04±0.02compared with the exact behavior ofr−2.00. The ring source exhibits the expected maximum. Not only does the apparatus provide a quantitative method for students to evaluate how the distance dependence of fields varies with source geometry, it also enables students to study ‘‘end effects’’ which provide insights into that commonly used statement ... ‘‘ignoring the ends we have ... .’’

ISSN:0002-9505    

DOI:10.1119/1.13919

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

Reports in May 1930 of an anomaly in the scattering and absorption of gamma rays, known as the Meitner–Hupfeld effect, presaged the New Physics of the 1930s. Scattering from light elements agreed with theoretical predictions based upon quantum electrodynamics and the relativistic electron theory of Dirac, but results on heavy targets pointed to a new nuclear absorption effect that was a harbinger of new particles and new phenomena. The experimental investigations of this anomalous absorption placed constraints on theories of nuclear structure, leading Heisenberg, for example, to insist upon the presence of electrons within nuclei as light as helium, even after Chadwick’s discovery of the neutron and Heisenberg’s proposed neutron–proton nuclear model. The anomalous γ‐ray behavior was eventually ascribed to electron–positron pair production and annihilation.

ISSN:0002-9505    

DOI:10.1119/1.13920

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

The movement of doubled strings is simulated on a device, described in the paper, which permits the main features of the motion to be seen in the classroom. When the strings move up and down together, the motion is heavily damped. For antisymmetric motion the damping rate is much smaller (the Weinreich mechanism). A simple model of the mechanism is discussed as it applies to the simulator. A less restricted solution of the coupled equations of motion is given in the Appendix.

ISSN:0002-9505    

DOI:10.1119/1.13921

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP

摘要:

We discuss an alternative method of performing coupling constant perturbation expansions in nonrelativistic quantum mechanics. This method, called logarithmic perturbation theory, yields new expressions for any‐order correctionsEnto an unperturbed bound‐state energy which do not involve cumbersome sums over intermediate unperturbed states. In one dimension, these correctionsEncan be evaluated using a simple explicit form containing a small number of integrals. In more than one dimension the approach is systematic but computations require the solution of well‐defined partial differential equations. For ordern=2 this equation is identical to that appearing in the method of Dalgarno and Lewis. Numerous illustrative examples are presented.

ISSN:0002-9505    

DOI:10.1119/1.13922

出版商:American Association of Physics Teachers    

年代:1984

数据来源: AIP