摘要:

The method of virtual work is applied to solve a number of problems in surface tension, and one problem in electrostatics. It is found that the solution is much simplified in many cases. The treatment is uniform in every case and is easily understandable.

ISSN:0002-9505    

DOI:10.1119/1.1935789

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

This course was set up for freshmen in architecture whose preparation in science and mathematics may be limited and whose major interests are elsewhere. Because most of the mathematical difficulties in a course in elementary physics appear in mechanics and electricity, we begin with sound, light, and heat, postponing mechanics and electricity to the second semester. This unconventional order of presentation has the added advantage that our students find the subjects of sound, light, and heat unexpectedly interesting, and immediately applicable to problems confronting the architect. In this part of the course much of the laboratory work is descriptive and only semiquantitative. The textbook is supplemented with three specially written chapters dealing with the architectural applications of sound, light, and heat, and one more which summarizes the fundamentals of electricity. A reference shelf is set up.

ISSN:0002-9505    

DOI:10.1119/1.1935790

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

Among the important, unique contributions lecture demonstrations can make to the effective teaching of physics are the following: 1. They confront the student with nature itself to an extent not possible in the laboratory. 2. They facilitate physical thinking. It is easier to theorize about a phenomenon after one has observed it directly. 3. For most students they provide unexcelled opportunities for observing, and thinking with, a physicist in action in a concrete problem situation. 4. They contribute to historical perspective and understanding, especially through the reenactment of classical observations or experiments, representing momentous discoveries.

ISSN:0002-9505    

DOI:10.1119/1.1935791

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

A subcritical assembly of natural uranium and ordinary water has been constructed at Haverford College as an educational instrument. Many of its parameters have been determined; their theoretical calculation and experimental measurement are discussed in the text.

ISSN:0002-9505    

DOI:10.1119/1.1935792

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

A simple example is given to show how confusion can result from an uncritical transfer of concepts between Newtonian and canonical (Lagrangian or Hamiltonian) formalisms.

ISSN:0002-9505    

DOI:10.1119/1.1935793

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

The number of images obtained by multiple reflection by two inclined plane mirrors is not, in general, independent of object position. Also, there is no single formula giving the number which holds good for every angle between the mirrors. One of the four rules laid down in this article can meet any general case with regard to the angle between mirrors or the object position.

ISSN:0002-9505    

DOI:10.1119/1.1935794

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

The problem of the “twins” concerns two twinsaandb. Withaat rest inS, we setbin motion, allow it to travel a certain distance, and then reverse the motion so that it returns to rejoina. In this problem, acts are performed onbwhile nothing is done toa. The problem of the effects of imparting motion to an entity is analyzed in the light of the discussion in Part I, and the customary conclusion is established to the effect that, as measured by heartbeats,bends the journey younger thana. The customary argument which produces the apparent paradox is to the effect that if we take our stand withbinS′, we seeamoving away fromb, then reversing its velocity with subsequent return tob, to find that it,a, is now younger thanb. It is pointed out that in this second view of the problem there is danger of envisaging a situation entirely different from that of the first problem. The danger lies in supposing that in the frame which accompaniesbsomething is done toa—in the reversal of its velocity. The second view of the matter should recognize that to secure the apparent reversal of velocity ofaas seen byb, we should notdo somethingtoafrom the frame ofb, but shoulddo somethingtobfrom the frame ofbitself. If the discussion is carried out in this manner, no paradox results.

ISSN:0002-9505    

DOI:10.1119/1.1935795

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

Further analysis is presented of a thought experiment due to Raymond, which permits an apparent violation of the second law of thermodynamics (the conversion of heat into work by a cyclic process), utilizing spontaneous fluctuations, and supplying the negentropy in the form of information obtained by counting. The thermodynamic efficiency of the heat engine itself is unity; considering the engine and counting demon together preserves the sanctity of the second law. An expression is derived for the power delivered by the engine, and the maximum value of this expression is studied as a function of the various parameters.

ISSN:0002-9505    

DOI:10.1119/1.1935796

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

The momentum space representation is discussed in general and an application is made, deriving the cross section of the photodisintegration of the deuteron, using the Hulthen wave function. The theoretical results are compared with the experimental values, and the Hulthen wave function parameter is determined.

ISSN:0002-9505    

DOI:10.1119/1.1935797

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP

摘要:

The density of states of spherical waves used in the calculation of low-temperature second virial coefficients of gases leads to an incorrect result when applied to the partition function of an ideal gas in a spherical box. A more accurate density of states is derived and shown to lead to the correct result. It is argued that the corrections play no role in the calculation of the second virial coefficient, and hence the known results for that case need no revision.

ISSN:0002-9505    

DOI:10.1119/1.1935798

出版商:American Association of Physics Teachers    

年代:1960

数据来源: AIP