摘要:

A classified tabulation of the regular articles of the American Journal of Physics for 1977 shows that the journal is properly described as a scholarly archival journal, a description which fits 80% of the regular articles published in that year. At most five regular articles, or 2%, would reasonably fit the category of educaton research.

ISSN:0002-9505    

DOI:10.1119/1.11832

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

We describe a new interdisciplinary course which explores the relations between physics and biology in terms of their conceptual structures and mathematical frameworks. The course is designed for senior undergraduate physics students who have little or no background in the life sciences. In this paper we highlight the course content, its system of cross‐disciplinary literature resources, and several innovative aspects of the method used for evaluating students.

ISSN:0002-9505    

DOI:10.1119/1.11833

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

One prediction for the appearance of the starfield from a moving reference frame has been circulated widely despite physically objectionable features. We reexamine the physical basis for this effect. To the well‐known aberation and Doppler effects we add the transformation of intensity of light upon a change of reference frame. We integrate the transformed spectrum of a star, represented as a blackbody, over the response function of the human eye. We present a one‐parameter function to represent the dependence of the apparent visual magnitude of different stars upon Doppler factor. We conclude with a sequence of computer‐generated figures to show the appearance of Earth’s starfield at various velocities. A ’’starbow’’ does not appear.

ISSN:0002-9505    

DOI:10.1119/1.11834

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

A specific round trip situation is set up, and is worked through from the point of view of each twin. The gravitational field equations, and geodesic equations of motion, are solved in the traveling twin’s reference frame, in order to determine the time elapsed on the Earth during the periods of acceleration. The equality of the results obtained by each twin is explicitly exhibited.

ISSN:0002-9505    

DOI:10.1119/1.11835

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

Considering a student’s examination as one state of a system which consists of the set of all possible examinations, a new method for evaluating multiple choice examinations is developed by measuring the entropy state of a student’s exam above the ’’thermal background level’’ (the most probable state). The entropy grade is shown to contain standard scoring as a special case when both the number of questions given and the number of possible selections become large. The entropy grade is also shown to be related to the information it takes a student to go from one state of understanding to another state of understanding. The student’s state of understanding is characterized either by his personal probability that his selections will be correct or by experimentally measured probability that the students’s selections were correct.

ISSN:0002-9505    

DOI:10.1119/1.11836

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

Some experiments on parametric effects, to be constructed by the students themselves, are described together with the discussion and questions given. Parametric oscillations were produced on a string, in a resonance circuit and a spring pendulum. The importance of phase relations for excitation of the oscillations and of nonlinearities in their stabilization was emphasized. The experiments were so organized that the students would meet unknown phenomena and problems; actually we discovered an unexpected recurrence effect in the spring pendulum.

ISSN:0002-9505    

DOI:10.1119/1.11837

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

The elliptic rangeREof a ballistic missile is the length of arc between the two intercepts of the circle of the earth with the elliptic orbit of the projectile. When expanded in powers of the projection velocityv,REis given byRE=2v2 sinϑ cosϑ/e+O(v6), whereeis the eccentricity of the orbit. Units are such thatGM=1 and the radius of the Earth is one. The lead term is thus the correct form for the solution to the elementary ballistic problem. It is shown that this lead term not only describes the flight of a snowball, but can also give a good account of the range of an ICBM. Thus, for a projection velocity ofv=√2/2 (half the escape velocity) the lead term gives the range for any angle of projection with less than a 2% error.

ISSN:0002-9505    

DOI:10.1119/1.11838

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

Factors influencing the premedical requirement in physics are examined. A review is given of the various reasons why physics is important in medical education. The new Medical College Admissions Test is discussed. In looking at the rapid advances in technology in medicine, it is argued that the medical student is presently disadvantaged in physics, simply not having taken enough physics as an undergraduate. It is urged that an additional (applied) course, requiring introductory physics and calculus as prerequisites, be included among medical school entrance requirements.

ISSN:0002-9505    

DOI:10.1119/1.11839

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

An effective demonstration of the phase relationships in a seriesRLCcircuit, resonance andQ, is made possible by multiplexing four signals onto a single channel thereby converting a single‐channel scope to four channels. With the circuit explained in the text, it is possible to present a simultaneous display ofVR,VL,VC, andVgenon a single‐channel scope. When theRLCcircuit is excited by a variable frequency generator,VRbecomes the reference phase. The time base ramp amplitude is made independent of the generator frequency by the circuit permitting four cycles of each waveform to always be in view on the scope, even though the generator frequency is varied from approximately 800 Hz to 18 KHz.

ISSN:0002-9505    

DOI:10.1119/1.11840

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP

摘要:

During the past three decades there has been considerable interest in the tensile strength of liquids. However, it is not generally realized that some pioneer experiments on the subjection of liquids to tension were carried out during the last century. Reynolds was one of the workers in this field and he was able to illustrate and measure the tension that a column of liquid could sustain. In the present paper this work of Reynolds is described and assessed and is compared with some of the other related work published in French journals in the last century.

ISSN:0002-9505    

DOI:10.1119/1.11841

出版商:American Association of Physics Teachers    

年代:1979

数据来源: AIP