ISSN:0002-9505    

DOI:10.1119/1.12248

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12252

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

If one drops the Faraday induction term from Maxwell’s equations, they become exactly Galilei invariant. This suggests that if Maxwell had worked between Ampère and Faraday, he could have developed this Galilei‐invariant electromagnetic theory so that Faraday’s discovery would have confronted physicists with the dilemma: give up the Galileian relativity principle for electromagnetism (ether hypothesis), or modify it (special relativity). This suggests a new pedagogical approach to electromagnetic theory, in which the displacement current and the Galileian relativity principle are introduced before the induction term is discussed.

ISSN:0002-9505    

DOI:10.1119/1.12239

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

Supersonic jet spectroscopy presents a way of studying extremely cold gas phase molecules without cryogenic apparatus. The spectra of cold molecules are generally easier to interpret than those of the same molecules at room temperature, thus facilitating the determination of molecular structure. Cooling also makes it possible to study weakly bound species such as van der Waals complexes. In addition, this technique is an interesting example of applications of gas kinetic theory. The paper discusses both the theory of supersonic jets and a typical experimental example.

ISSN:0002-9505    

DOI:10.1119/1.12276

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

The relationships between the probabilitiesp,x,s, andM, of winning, respectively, a point, a game, a set, or a match have been derived. The calculations are carried out under the assumption that these probabilities are averages. For example,xrepresents an average probability of winning a game when serving and receiving, and the same value ofxis assumed to hold also for tie‐break games. The formulas derived are for sets played with a tie‐break game at the level of 6–6, as well as for the traditional rule requiring an advantage of two games to win a set. Matches to the best of three and five sets are considered. As is to be expected, a small advantage in the probabilitypof winning a point leads to advantages which are amplified by large factors : 2.5 for games, 7.1 for sets with tie‐break at 6–6, 10.6 for matches to the best of three sets, and 13.3 for matches to the best of five sets. When sets are decided according to the traditional rule, the last three factors become, respectively, 7.4, 11.1, and 13.8. The theoretical calculations are compared with real and synthetic tennis scores and good agreement is found. The scatter of the data is seen to obey the predictions of a normal distribution. Some classroom problems are suggested at the end.

ISSN:0002-9505    

DOI:10.1119/1.12241

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

The high degree of specialization prevalent in the traditional education of contemporary physicists has worked to the detriment of the profession on occasion in recent history. Many careers have been salvaged by switching fields and adapting basic training already acquired to fruitful pursuits in other areas. Such broadening might well be a part of the educational process, but it will require alternative structures in curriculum programming. Data gathered in a national survey are presented which support the case for a physical scientist broadly educated in applied areas. The paper argues that physical scientists should compete for a larger share of the industrial job market; however, the competition will require flexibility in program packaging and some shifting of the types of educational experiences made available to students.

ISSN:0002-9505    

DOI:10.1119/1.12242

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

Common laboratory apparatus and readily available materials are used to generate resonance spectra of air columns. Frequency measurements of the harmonics of a column match very well with theoretical calculations. Three additional experiments are described, involving the end correction to the column length, tone holes in the side of the column and the addition of a bell to the end of the column.

ISSN:0002-9505    

DOI:10.1119/1.12243

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

When acoustic or electromagnetic waves cancel by destructive interference, the wave impedance reflected to the sources of the wave energy changes so that the input power is reduced correspondingly. Because this rather subtle point is not discussed in most instructional treatments of wave physics, misconceptions concerning the apparently ’’missing’’ energy are widespread, as reflected in semipopular science writing. This paper presents an analysis of the cases of destructive and constructive wave interference, and analogous problems for lumped electrical and mechanical systems.

ISSN:0002-9505    

DOI:10.1119/1.12244

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

Room reverberation measurements and their interpretation are an important part of a musical acoustics course which has proved successful with nonscience students at the State University of New York College at Oswego. This paper describes these measurements in detail along with a variety of ways they can be used in the classroom.

ISSN:0002-9505    

DOI:10.1119/1.12245

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP

摘要:

In this paper we attempt to verify a nongyroscopic theory of bicycle stability, and fail.

ISSN:0002-9505    

DOI:10.1119/1.12246

出版商:American Association of Physics Teachers    

年代:1980

数据来源: AIP