摘要:

A simple, inexpensive student potentiometer of moderate accuracy is discussed, along with a somewhat different calibration source. The calibration source is ac operated, and short-circuit proof. Both the potentiometer and the calibration source were made from readily available commercial parts. Stability of the source is adequate for the 0.1% accuracy of the potentiometer. Long-term temperature stability is only moderate, but short-term stability is outstanding.

ISSN:0002-9505    

DOI:10.1119/1.1972010

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

A simple graphical method for integrating the equation of motion of a particle inanyfield of force is used as a short laboratory exercise in an introductory course in mechanics. No knowledge of calculus nor differential equations is required of the student. Based directly on the vector definitions of average velocity and acceleration, and on central differences, it is capable of reasonable precision with relatively large steps. Using the three numbers,6560cm3 = r2a(2τ)2,53.7 cm = x1 = x−1, and4.5 cm = y1 = −y−1, the student can develop half an elliptical orbit in 10 steps to about 6% accuracy on a 56 by 86-cm paper sheet in about one hour, and he can see for himself the step-by-step progress of a particle in an inverse-square field. The considerations leading to these or similar numbers are discussed briefly.

ISSN:0002-9505    

DOI:10.1119/1.1972012

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

The Feynman Lectures on Physics, Vol. 1, are reviewed to illustrate some features common to many new physics courses.

ISSN:0002-9505    

DOI:10.1119/1.1972014

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

A survey was conducted to determine the type of introductory physics courses that is being offered in college physics departments and whether special courses are offered for those students who have completed high-school physics. Analysis of the questionnaires indicates that very few colleges or universities offer special consideration to these students. Representative comments made by the respondents to the survey are given, and some of the problems which are raised are discussed. Suggestions are made for future study needed to arrive at possible solutions to these problems.

ISSN:0002-9505    

DOI:10.1119/1.1972017

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

In an attempt to throw some light on the controversies over the foundations of quantum mechanics, the author presents what he believes to be the philosophical viewpoint (namely, “idealism”) underlying Bohr's interpretation of quantum mechanics and then illustrates this with some typical passages by Bohr. Why the “realist” might find this interpretation unsatisfactory is briefly indicated by some statements by Einstein.

ISSN:0002-9505    

DOI:10.1119/1.1972023

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

The paper describes the construction and use of a simple photometer consisting of a small photoconductive cell mounted so that it can be moved smoothly across an interference fringe system. The detector width is about 0.005 in. The photoconductive current is measured with a commercial electrometer or with a simple transistorized amplifier. Intensity distributions as measured with the photometer are shown for single, double and triple slits, and for a straight edge. The paper also describes the use of the photometer to illustrate the principle of Michelson's stellar interferometer, by making measurements of the visibility of double-slit fringes as a function of the width of the light source.

ISSN:0002-9505    

DOI:10.1119/1.1972028

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

An elementary method is described for enumerating near neighbors of an ion in a composite lattice where the ion positions are determined by symmetry. The method is illustrated by examples.

ISSN:0002-9505    

DOI:10.1119/1.1972033

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

We present a design for a simple Rutherford Scattering Simulator based on elastic collisions of small spheres with a modified parabolic cylinder.

ISSN:0002-9505    

DOI:10.1119/1.1972038

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

In a widely-used version of the periodic table, lanthanum is classed in the same column with scandium and yttrium. However, in a number of respects lutetium resembles scandium and yttrium more closely than lanthanum does. Hence the periodic table should be modified so that scandium, yttrium, and lutetium are in the same column.

ISSN:0002-9505    

DOI:10.1119/1.1972042

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP

摘要:

A development of the theory of special relativity is based on a principle of relativity for inertial frames as applied to mechanical phenomena only. The Lorentz-transformation equations and the familiar mass-variation formula are deduced from the observation that mass does vary with speed; but in these the speed of lightcis everywhere replaced by a universal speedk—namely, the speed at which the mass of any particle must become infinite—which arises as a consequence of the assumptions. The experimental result that the free-space speed of light with respect to the earth is equal tokthen implies the same free-space speed of light with respect to every inertial frame—the usual starting point of the theory.

ISSN:0002-9505    

DOI:10.1119/1.1972047

出版商:American Association of Physics Teachers    

年代:1965

数据来源: AIP