摘要:

The hidden variable theorem due to von Neumann is deduced in a physically transparent manner. As a result it is clear that the theorem is correct only if one requires that these hidden variables merely enlarge the set of observables employed at present in quantum mechanics. The theorem cannot be interpreted to mean that one cannot introduce such additional variables in order (1) to specify a state with classical completeness and (2) to define the usual observables as statistical parameters.

ISSN:0002-9505    

DOI:10.1119/1.1934581

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

A review of the periodical literature on the subject of impact and the coefficient of restitution ε shows that it depends not only on the materials (elastic moduli) of the colliding objects, but also on (1) their relative normal velocity at the instant of impact, (2) their shapes and sizes, (3) their masses, and (4) the medium in which the impact occurs.

ISSN:0002-9505    

DOI:10.1119/1.1934583

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

A survey of physics and engineering textbooks indicates that there is lack of agreement among the authors on the subject of impact and the coefficient of restitution as well as disagreement between the textbook authors and the writers of the articles in the periodicals. The confusion arises primarily because of (1) the way in which the coefficient of restitution ε is so often defined, (2) the nature of the usual discussions of it, and (3) the reason given for ε being less than unity for most collisions between objects of ordinary size. Ways of eliminating the difficulty are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1934584

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

A 6-in. diameter Wilson Cloud Chamber was constructed by six senior students as a project in an atomic and nuclear physics course. The planning and actual machine work were student performed and several good pictures of alpha tracks were made using the apparatus.

ISSN:0002-9505    

DOI:10.1119/1.1934585

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

The author believes that the optical path method should be used more widely than it is at present in the teaching of geometrical optics. As illustrations of the use of the method, spherical aberration and astigmatism of a spherical surface are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1934586

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

The usual definition of spin in the Dirac theory brings about peculiar results which one finds difficult to visualize from an intuitive standpoint. An approach to this problem utilizing the framework of the Foldy-Wouthuysen representation is suggested. Applications to the description of polarization of beams and scattering experiments are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1934587

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

The effect may be demonstrated by a flame of coal gas directed toward a surface of a soap solution. A rapid flow of surface layer toward the flame, a surface elevation of several millimeters, and a downward current under the elevation will occur. Rough measurements of the tension by means of drop methods (1) at room conditions and (2) near a flame show an increase from 29 to 57 dyne/cm for a certain solution. The effect of the hot gases may be to restore the conditions of the surface to those of clean water.

ISSN:0002-9505    

DOI:10.1119/1.1934588

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

The principle of the multiple-stage rocket is reviewed. It is shown that the burn-out velocity of a multiple-stage rocket is higher than that of a single-stage rocket of the same over-all mass ratio. It is also shown that the over-all pay-load ratio of a multiple-stage rocket required to reach a given velocity is minimum when the pay-load ratios of all stages are equal. Departure from this equality is demonstrated to have little effect on the over-all pay-load ratio.

ISSN:0002-9505    

DOI:10.1119/1.1934589

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

摘要:

More reliable techniques are needed for evaluating laboratory instruction in general physics. The advantages and disadvantages of objective-type tests are presented. The applications of multiple-choice items in the laboratory are discussed. There is need for research on evaluating laboratory instruction.

ISSN:0002-9505    

DOI:10.1119/1.1934590

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934591

出版商:American Association of Physics Teachers    

年代:1958

数据来源: AIP