摘要:

This paper reports our experiences with open-end introductory-physics laboratories after three semesters. All available indications show that they are successful. The method of evaluation of the effectiveness of the open-end laboratories and the results are given. Organizational details and changes in the organization made for 1969–1970 are also included. An important device used to start the student on an open-end experiment is a required preset exercise.

ISSN:0002-9505    

DOI:10.1119/1.1976366

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

In the present paper, we analyze the problem of an arbitrary number of particlesAin a harmonic-oscillator common potential interacting through a harmonic-oscillator force. The particles have spin12and obey Fermi statistics. The exact lowest eigenstate and energy are derived for values ofAcorresponding to closed subshells. An approximate analysis is also made using determinantal wave functions formed from single-particle harmonic-oscillator states, giving the eigenstates and energies of a simple form of the Hartree-Fock approximation. The exact and Hartree-Fock energies and eigenstates are compared both when potential and force have the same sign, and when they have opposite sign. We discuss the results for models which we call pseudonuclei and pseudoatoms, and we indicate some of the inferences for the real thing.

ISSN:0002-9505    

DOI:10.1119/1.1976367

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The Moravek-Joseph method [P. H. Moravek and D. W. Joseph, J. Math. Phys.4, 1363 (1963)] for the construction of unitary operators in quantum field theory is found to be applicable also to nonrelativistic quantum mechanics. Some simple examples are given.

ISSN:0002-9505    

DOI:10.1119/1.1976368

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

A one-dimensional model of an atom is proposed that simulates some of the wavelike characteristics of the hydrogen atom. The model consists of an elastic string under tension in which the transverse waves simulate the ψ wave of the electron in an atom, and the waves of varying tension simulate the electromagnetic waves interacting with the atom. Because of its simplicity, the model may be useful, for teaching purposes, in introductory quantum mechanics courses.

ISSN:0002-9505    

DOI:10.1119/1.1976369

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

Apparatus suitable for measurements of the thermoelectric power of wires in the temperature region from 77 to 300 K is described. An outline of the theoretical treatment of thermoelectric power is presented and typical results are given for aluminum, gold, and iron. This experiment has been used in the undergraduate advanced laboratory.

ISSN:0002-9505    

DOI:10.1119/1.1976370

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

A numerical technique is used to determine the manner in which the expectation values of position for an electron in an infinite tilted well depend on the potential gradient and quantum state of the system. The results are compared to the classical case and to the exact analytic expression for the special case in which the total energy of the electron is equal to the maximum value of the linear potential.

ISSN:0002-9505    

DOI:10.1119/1.1976371

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The behavior of the Schwarzschild metric inside the gravitational radius is compared to the behavior of the flat space metric in rotating coordinates whenrω > 1. In both cases the time is imaginary and the spatial line element indefinite with regard to sign. In both cases the physical interpretation is the same: Observers at rest (in the coordinate system) do not exist.

ISSN:0002-9505    

DOI:10.1119/1.1976372

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The representation of a magnetic field by the cross product of the gradients of two scalars has recently seen wide use in plasma physics and in the study of energetic particles in space. The properties of such a representation are reviewed and examples of its application are given.

ISSN:0002-9505    

DOI:10.1119/1.1976373

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

The current definition of the comomentum associated with a moving charge is discussed, and it is shown to be unsuitable for a charge undergoing nonuniform motion. An alternative definition is then proposed for a charged particle of vanishingly small size, and it is demonstrated that this definition is satisfactory for a charge in arbitrary motion.

ISSN:0002-9505    

DOI:10.1119/1.1976374

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP

摘要:

As an illustration of a general method for calculating the circuit response of a network subjected to a periodic signal, the case of an RC circuit driven by a square-wave generator is worked out in complete detail for three values of a circuit parameter. A computer is used to add a sufficient number of Fourier sinusoidal terms and to plot out the circuit response. A criterion for the number of terms needed is given. For comparison, the exact solution is also presented. Experimental verification is achieved by photographing the screen of an oscilloscope which is connected across the proper circuit element. The resulting photographs are enlarged (in effect) to the exact size of the computer plots onto transparent film. An overlay of the transparencies on the computer plots give excellent agreement.

ISSN:0002-9505    

DOI:10.1119/1.1976375

出版商:American Association of Physics Teachers    

年代:1970

数据来源: AIP