摘要:

When changing units and in dimensional analysis it is usual to employ the relation,physical quantity = measure×unit. Neither the “physical quantity” nor the “unit” is supposed to be a real number and yet the formalism is normally effective. This fact is given a rational explanation and the ideas involved are used to discuss certain questions connected with the rationalization of the electromagnetic equations.

ISSN:0002-9505    

DOI:10.1119/1.1933423

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

An interesting illustrative problem in mechanics is the motion executed by a vertical rod or column when it suffers sudden loss of support at the bottom. A solution is presented by the method of Laplace transform in two alternative forms: one represents the motion as a superposition of free fall and two oppositely directed progressive waves equal in amplitude and form; the other, as a free fall and a pulse, initiated at the bottom and propagated up and down the column upon reflection at the ends.

ISSN:0002-9505    

DOI:10.1119/1.1933424

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Since the symbols—names, or their abbreviations—for physical units may be incorporated in physical equations in exactly the same manner as are the letter symbols for physical quantitiesand the numerical symbols, it follows that the rules for selecting and using these unit-symbols should be formulated in the light of established mathematical procedures. A set of such rulesis proposed. Symbols are suggested for 185 commonly used units and combining forms.

ISSN:0002-9505    

DOI:10.1119/1.1933425

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

A course in electrical measurements is described wherein the emphasis is shifted from the learning of various electrical measuring techniques to the development of an appreciation of experimental problems in general. This is accomplished by dropping the requirement of written reports, by allowing sufficient time for the performance of each experiment for thoughtful work, and by selecting the experiments for certain features of general experimental significance rather than for specific electrical measuring techniques. Examples are given of typical experiments.

ISSN:0002-9505    

DOI:10.1119/1.1933426

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

The curriculum of the Oak Ridge School of Reactor Technology includes a laboratory course in reactor physics. The first experiments are concerned with the fundamentals of nuclear physics and the later ones are of direct relevance to reactor engineering. The laboratory manual of the course is available as AECU-2164.

ISSN:0002-9505    

DOI:10.1119/1.1933427

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

The role that pulverization of the target material may play in absorbing the energy of an impacting missile is discussed. The energy that can be absorbed in this way will, in general, depend on the area of new surface that is created. Approximate calculations suggest that, for impacts against rock-like materials and glass, very considerable amounts of energy could be absorbed. The production of rock flour at the Barringer Meteorite Crater in Arizona is cited as an example.

ISSN:0002-9505    

DOI:10.1119/1.1933428

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Simple apparatus, using a scintillation counter with a 931-A photomultiplier, is described. The range of alpha-particles fromPo210is determined with this apparatus by varying the pressure in a shielded container, keeping the geometry constant. Data are presented on a 0.06 millicurie source, yielding a range of (3.81±0.03) cm at 760 mm Hg and 15°C. This value is obtained after correction for finite source thickness. The experiment offers particular value in giving students an opportunity to consider statistical fluctuations and to analyze the effects of finite source thickness, straggling, etc.

ISSN:0002-9505    

DOI:10.1119/1.1933429

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

In the relativistic theory of one-dimensional rocket motion in empty space, Ackeret has found the differential equation of motion and the mass-ratio formula. One can obtain a formal solution for theintegrated equation of motionX = X(T)in the general case by determiningXandTparametrically as functions of the proper timesof the rocket.

ISSN:0002-9505    

DOI:10.1119/1.1933430

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933432

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933433

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP