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1. |
Units and Dimensions in Physics |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 1-4
C. H. Page,
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摘要:
The equations of physics are often interpreted as purely numerical relations. Endowing the symbols with “dimensional” quality as well as magnitude leads to a simpler, yet rigorous, mathematical structure, and permits changing units by direct substitution. Analysis of the mathematical universe of discourse of physical equations shows also that the four-dimensionall,m,t,qsystem of units is actually simpler than a three-dimensional system.
ISSN:0002-9505
DOI:10.1119/1.1927482
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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2. |
Meson Masses and Energetics of Meson Decay |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 5-13
Walter H. Barkas,
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摘要:
A series of measurements of theπ- and μ-mesonmasses and their decay energies is reviewed. Recent mass measurements made at the University of California Radiation Laboratory have employed an improved method in which the ratio of theπ-mesonmass to that of the proton and the ratio of theμ-mesonmass to that of theπ-mesonwere determined by measuring the ratios of ranges and ratios of momenta for particles of equal velocities. The absolute decay momentum of theμ-mesonwas also determined in the same series of experiments. Other experiments at the Radiation Laboratory in which quite different methods were used to obtain theπ-mesonmass and the decay energy of theμ-mesonare also discussed. The measurements are consistent with aπ-mesonmass of 276 electron masses and aμ-mesonmass of 210 electron masses. In addition, no contradiction is found for the assumptions that theπ − μdecay is accompanied by a neutrino and theμ − edecay is accompanied by two neutrinos.
ISSN:0002-9505
DOI:10.1119/1.1933092
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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3. |
Comic Dictionary of Physical Terms |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 13-13
Marge M. Muller,
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PDF (72KB)
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ISSN:0002-9505
DOI:10.1119/1.1933093
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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4. |
Shapes of Craters Formed in Plaster of Paris by Ultra-Speed Pellets |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 14-18
John S. Rinehart,
W. C. White,
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PDF (910KB)
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摘要:
Observations have been made on the craters produced in plaster of Paris targets by steel pellets that weighed 2 g and impacted at a velocity of 2.5 km/sec and by aluminum pellets that weighed23 gand impacted at a velocity of 4.7 km/sec. The angle of impact was varied from normal incidence to 75°. For angles of incidence between 0° and 45°, the mouth of the crater was substantially circular. At 60°, it had roughly the shape of an arrowhead. At 75° obliquity, the pellet ricocheted and produced an elliptical crater.The area of the mouth of the crater in every case was many times the area of the impacting particle. The craters were characterized by a large bowl-shaped excavation from12in. to 1 in. in depth with a shaft that extended a few inches into the plaster and whose area was approximately that of the pellet.The volumes of the holes have been measured and related to the impacting energy and momenta of the respective pellets.
ISSN:0002-9505
DOI:10.1119/1.1933094
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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5. |
Physics Cooperates with Civilian Defense |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 19-23
Frank G. Karioris,
Arthur G. Barkow,
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摘要:
A report on the Radiological Monitoring Course offered as part of the Milwaukee Civilian Defense Program. In the first course 250 firemen, policemen, and people with technical background were trained in the principles of nuclear physics, and the effects, detection, and measurements of radiation. The course consisted of a series of lectures, together with appropriate films on the fundamentals of atomic and nuclear physics. The laboratory sessions consisted in familiarizing the trainees in the handling, reading, and care of three different radiation measuring instruments. Small radium sources were used. The field sessions consisted of the survey of a three curie cobalt-60 source at a local football stadium.
ISSN:0002-9505
DOI:10.1119/1.1933095
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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6. |
A Laboratory Experiment with Coupled Linear Oscillators |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 23-25
Franklin Miller,
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摘要:
Two rolling masses and three helical springs are arranged collinearly in a horizontal plane. Longitudinal vibrations of the system are excited manually and the two normal modes studied. Calculated and observed frequencies can be compared in detail, since the coupling constant is directly measured. Agreement is obtained to within a few percent.
ISSN:0002-9505
DOI:10.1119/1.1933096
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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7. |
Quantitative Evaluation of Rocket Propellants |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 26-31
S. S. Penner,
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摘要:
A method for the quantitative evaluation of chemicals as rocket propellants is described. The procedure utilizes the fact that adiabatic expansion through a nozzle may be considered to be isentropic. Treatments are presented for the two limiting conditions of expansion, corresponding to flow without chemical change and to flow which is characterized, at all times, by the existence of thermodynamic equilibrium.
ISSN:0002-9505
DOI:10.1119/1.1933097
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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8. |
The Tesla Coil |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 32-35
James B. Kelley,
Lee Dunbar,
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PDF (1122KB)
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摘要:
A description of the construction and operation of a replica of a coil, such as Nikola Tesla first described in 1891, is presented.
ISSN:0002-9505
DOI:10.1119/1.1933098
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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9. |
Statistical Fluctuation in Radioactive Phenomena |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 35-37
J. A. Grundl,
F. G. Karioris,
A. G. Barkow,
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PDF (357KB)
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摘要:
An experiment applicable to an intermediate laboratory course in modern physics is presented. The method is fundamentally that used in 1910 by Rutherford and Geiger, with a G-M scaler and tape recorder replacing the scintillation technique. The experiment establishes the random nature of radioactive decay and introduces the student to the concept of statistical fluctuation.
ISSN:0002-9505
DOI:10.1119/1.1933099
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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10. |
Space at Mid-Century |
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The American Physics Teacher,
Volume 20,
Issue 1,
1952,
Page 38-49
Richard Schlegel,
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摘要:
The concepts of space which are used in contemporary physics are discussed, and are contrasted with the older concepts associated with Newtonian physics. The effects of uniform motion on space and the simplest currently accepted relations between space and time are stated. Deviations from three-dimensional orthogonal space as demanded by the general theory of relativity are discussed, with attention to the relative roles of space and time terms in the space-time curvature associated with gravitational fields. The development of cosmo-logical theory, on the basis of general relativity concepts, is briefly indicated. Mach's suggestion for the relation of matter and space is described; more recent speculations relating over-all space and local properties, and the possibility of discontinuity in microscopic space, are noted. The emphasis in the current conception of space on interdependence between space and matter is pointed out.
ISSN:0002-9505
DOI:10.1119/1.1933100
出版商:American Association of Physics Teachers
年代:1952
数据来源: AIP
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