ISSN:0002-9505    

DOI:10.1119/1.14773

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.14777

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.14779

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.14782

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

Fermat’s principle may be used to derive an equation, of the formF=ma, governing the shape of a light ray in a medium of varying refractive index. Many interesting problems in gradient‐index optics that ordinarily require considerable computation may therefore be solved very simply by analogy to familiar mechanical problems. This approach also provides the means of thoroughly exploring the optical‐mechanical analogy at a much more elementary level than is usual.

ISSN:0002-9505    

DOI:10.1119/1.14861

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

The abstract theory of probability and its interpretation are briefly reviewed, and it is explicitly demonstrated that the formalism of quantum mechanics satisfies the axioms of probability theory. This refutes the suggestions which have occasionally been made that ‘‘classical’’ probability theory does not apply to quantum mechanics. Several erroneous applications of probability theory to quantum mechanics are examined, and the nature of the errors are exposed. It is urged that more attention be given to probability theory in the physics curriculum.

ISSN:0002-9505    

DOI:10.1119/1.14783

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

Some interpretations of quantum mechanics try to describe the probabilistic nature of quantum measurements in a way that allows a system in a pure state to always have precise (if not simultaneously knowable) values for all its observable variables. In what might be called asimpleensembleinterpretation, the quantum mechanical state vector is assumed to define a statistical ensemble of identically prepared systems, each of which has precise values for all its observable variables, and the act of measurement is equivalenced to a straightforward sampling of that ensemble. It is shown here, in a manner that should be suitable for a first course in quantum mechanics, that a simple ensemble interpretation is not possible for some quantum systems, and hence is untenable as a general premise. The analysis is essentially a repackaging of the Bell argument against hidden variables, although hidden variables are never invoked here.

ISSN:0002-9505    

DOI:10.1119/1.14784

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

The polaroid ultrasound ranging system has been interfaced to an Apple IIe computer. Sufficient resolution is achieved to permit calculation of velocity and acceleration derivatives. The interface is described and the graphical results of several air‐track experiments are presented.

ISSN:0002-9505    

DOI:10.1119/1.14867

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

A sphere, attached to the end of a spring, is immersed in glycerin. The motion of the sphere was videotaped as it traveled toward the equilibrium position and we compared the position‐versus‐time measurements from each frame of the videotape with theoretical calculations to extract the viscosity. Dropping the sphere in glycerin and using videotapes to find the terminal speed also yields the viscosity of glycerin.

ISSN:0002-9505    

DOI:10.1119/1.14785

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP

摘要:

A sphere, on one side of an Atwood machine, is immersed in glycerin and permitted to fall. We timed the descent and measured the terminal speed. We varied the massm2on the other side of the Atwood machine and plotted a graph of the terminal speed versus massm2. Both the slope and the intercept yield the viscosity.

ISSN:0002-9505    

DOI:10.1119/1.14786

出版商:American Association of Physics Teachers    

年代:1986

数据来源: AIP