摘要:

An explicit construction of the time‐dependent Lagrangian for a damped harmonic oscillator is given. The connection between this Lagrangian with the time‐independent one developed by Morse and Feshbach is established. Various methods of deriving a first integral for the equation of motion are given. It is shown that the results developed in this paper by direct means are in agreement with those obtained through the use of group‐theoretic methods, such as invariance principles and Noether’s theorem, which are mathematically more advanced approaches.

ISSN:0002-9505    

DOI:10.1119/1.12644

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

摘要:

An example of the geometric treatment of a classical force is presented as a concrete illustration of the principle of covariance, an idea that is basic to general relativity. The manner in which the force components are accounted for by the Christoffel symbols associated with the model geometry is easily seen because of the familiar nature of the three‐dimensional, classical, example. We then briefy indicate how this three‐dimensional case can be extended to the four‐dimensional geometries of general relativity. Making contact between classical examples and general relativity is usually done via the principle of equivalence, which involves coordinate systems in relative motion. Our example involves the geometric model that represents a single coordinate system.

ISSN:0002-9505    

DOI:10.1119/1.12645

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

摘要:

By differentiating the radial equation with separable potentials of exponential form, a differential equation with constant coefficients is obtained. The Yamaguchi potential is used as the principal example in deriving bound‐state and scattering solutions in a simple approach that elucidates the correspondence between the poles of the scattering amplitude and the roots of the bound‐state problem.

ISSN:0002-9505    

DOI:10.1119/1.12646

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

摘要:

A general expression for stimulated transition rates between two levels of an atomic system is developed. This expression not only applies for an arbitrary radiation field, but it also includes the effects of line broadening on transition rates. The general expression is used to obtain the rate equation for the spectral photon number density per steradian for a given pair of atomic energy levels. The result is applied to two special cases by integrating over the spectral and angular ranges of interest.

ISSN:0002-9505    

DOI:10.1119/1.12647

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

摘要:

The authors present a way of performing the spring experiment that requires more personal involvement on the part of the student.(AIP)

ISSN:0002-9505    

DOI:10.1119/1.12650

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12582

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12583

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12723

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12584

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.12585

出版商:American Association of Physics Teachers    

年代:1981

数据来源: AIP