摘要:

The version of Fresnel's formula for the convection coefficient is given in different forms (for dispersive media) in different textbooks. The differences are often confusing. The reasons for this situation are analyzed, and the interconnections between the various formulas are shown.

ISSN:0002-9505    

DOI:10.1119/1.1974296

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A baseball fielder will arrive at the right place at the right time to catch a fly ball if he runs at the only constant velocity for which the rate of change of tangent of the elevation angle of the ball and the bearing angle of the ball both remain constant. Remarks are made concerning curve balls. Baseball is not a scientific game—although, unknown to the players, many principles of physics can be applied to it.

ISSN:0002-9505    

DOI:10.1119/1.1974297

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

Octonions, or Cayley numbers, are used to extract the square root of the classical relativistic Hamiltonian, in place of the usual Dirac matrices. The resulting wave equation, analogous to the usual Dirac equation, is found to be equivalent to a pair of coupled Dirac equations. Thus, the introduction of the octonion algebra in place of the Dirac algebra provides nothing new in principle within the context of linear relativistic wave equations.

ISSN:0002-9505    

DOI:10.1119/1.1974298

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

Laboratory experience and the theoretical aspects of physics must merge for a complete and thorough introductory physics program. A new approach to the laboratory experience has been under study and development during the past five years at Orlando Junior College, a private institution with a physics (1966–1967) enrollment of 105 students from a student body of 2361. Obvious trademarks of this laboratory are a diversity of interests, educational excellence, and economy. Thirty permanent experimental stations, seventy other experiments on open shelving, total blackout booths for optics, a single-concept film booth, a director's office in the laboratory, and an adjoining small class or seminar room show the efficiency of this plan. A description of the organization and attractiveness of the laboratory as well as its unique utilization of wall, ceiling, and floor space is given in this paper.

ISSN:0002-9505    

DOI:10.1119/1.1974299

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

An experiment is described that requires a minimum amount of equipment usually found in the undergraduate physics laboratory. The experiment is designed to serve as an introduction to eigenfrequencies. It consists of two equal lengths of different-density thin wires joined and held horizontally under a known tension. One section of the wire sits in a magnetic field of a simple horseshoe-type magnet. If a current from an audio generator is passed through the wire, the interaction between the two magnetic fields causes the wire to undergo oscillations. Resonance occurs when the frequency of the oscillator is a normal mode frequency of the two-wire system.

ISSN:0002-9505    

DOI:10.1119/1.1974300

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A simple undergraduate experiment on Moseley's law is discussed. Illustrative data are given. The apparatus consisted of a57Cosource, a proportional counter, a preamplifier, and an oscilloscope. Various extensions of the work into semi-independent projects are also suggested.

ISSN:0002-9505    

DOI:10.1119/1.1974301

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

The values are presented for including the concepts and laws of fluid dynamics within physics programs. The extent of teaching and the extent of knowledge expected of a graduate have been found by a survey of U.S. schools. Proposals are made for helping physics teachers include more about fluids in their courses and curricula and a list of topics constituting fluid dynamics as a part of physics is included.

ISSN:0002-9505    

DOI:10.1119/1.1974302

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

An argument is given that teaching relativity from the beginning using four-vectors provides a powerful and correct way of thinking that also conforms to everyday methods of making measurements. In particular, it is pointed out that the emphasis on the relativistic mass is both undeserved and misleading.

ISSN:0002-9505    

DOI:10.1119/1.1974303

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

摘要:

A simple-straightforward derivation of the most general form of the homogeneous Lorentz transformation is presented. In the process, the well-known decomposition of a generic element of the group into two pure rotations and a “one-dimensional” Lorentz transformation is obtained in a physically obvious manner.

ISSN:0002-9505    

DOI:10.1119/1.1974304

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1974305

出版商:American Association of Physics Teachers    

年代:1968

数据来源: AIP