Browse - American Journal of Physics

Keyword
Volume/Page
DOI
Advanced

Search Content Type

Volume: Page/Article:

article doi:

American Journal of Physics»
Browse»

SECTION LISTING

BROWSE VOLUMES

Year Range:

2012

Volume 80

2011

Volume 79

2010

Volume 78

2009

Volume 77

2008

Volume 76

2007

Volume 75

2006

Volume 74

2005

Volume 73

2004

Volume 72

2003

Volume 71

2002

Volume 70

2001

Volume 69

2000

Volume 68

1999

Volume 67

1998

Volume 66

1997

Volume 65

1996

Volume 64

1995

Volume 63

1994

Volume 62

1993

Volume 61

1992

Volume 60

1991

Volume 59

1990

Volume 58

1989

Volume 57

1988

Volume 56

1987

Volume 55

1986

Volume 54

1985

Volume 53

1984

Volume 52

1983

Volume 51

1982

Volume 50

1981

Volume 49

1980

Volume 48

1979

Volume 47

1978

Volume 46

1977

Volume 45

1976

Volume 44

1975

Volume 43

1974

Volume 42

1973

Volume 41

1972

Volume 40

1971

Volume 39

1970

Volume 38

Issue 12 | Dec 1970 | pp. 1373-1505

Issue 11 | Nov 1970 | pp. 1273-1371

Issue 10 | Oct 1970 | pp. 1169-1272

Issue 9 | Sep 1970 | pp. 1071-1167

Issue 8 | Aug 1970 | pp. 949-1070

Issue 7 | Jul 1970 | pp. 795-948

Issue 6 | Jun 1970 | pp. 675-788

Issue 5 | May 1970 | pp. 557-669

Issue 4 | Apr 1970 | pp. 407-553

Issue 3 | Mar 1970 | pp. 279-404

Issue 2 | Feb 1970 | pp. 129-276

Issue 1 | Jan 1970 | pp. 3-128

1969

Volume 37

1968

Volume 36

1967

Volume 35

1966

Volume 34

1965

Volume 33

1964

Volume 32

1963

Volume 31

1962

Volume 30

1961

Volume 29

1960

Volume 28

1959

Volume 27

1958

Volume 26

1957

Volume 25

1956

Volume 24

1955

Volume 23

1954

Volume 22

1953

Volume 21

1952

Volume 20

1951

Volume 19

1950

Volume 18

1949

Volume 17

1948

Volume 16

1947

Volume 15

1946

Volume 14

1945

Volume 13

1944

Volume 12

1943

Volume 11

1942

Volume 10

1941

Volume 9

1940

Volume 8

1939

Volume 7

1938

Volume 6

1937

Volume 5

1936

Volume 4

1935

Volume 3

1934

Volume 2

1933

Volume 1

Select this Article		Resource Letter TLA-1 on Technology, Literature, and Art since World War II William H. Davenport American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 407 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract Prepared at the request of the AAPT Committee on Resource Letters. This is one of a series of Resource Letters on different topics, intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and suggestions concerning the content and arrangement of letters as well as suggestions for future topics will be welcomed. Please send such communications to Professor Joel Gordon, Chairman, Resource Letter Committee, Department of Physics, Amherst College, Amherst, Massachusetts 01002. Additional copies: Available from the Executive Secretary, American Association of Physics Teachers, 335 East 45 Street, New York, N. Y. 10017. When ordering, request Resource Letter TLA-1 and enclose 25 cents per copy (not in stamps), together with a self-addressed stamped envelope.

Select this Article		The Potential of a Point Charge between Capacitor Plates M. L. Glasser American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 415 \| Cited 2 times Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract The potential of a point charge between two grounded conducting plates is expressed as a definite integral, simplifying a previous formula due to Pumplin. The potential is obtained exactly in closed form along a line passing through the charge.

Select this Article		A Helicon Solid-State Plasma Experiment for the Advanced Laboratory J. R. Merrill, D. Pierce, and D. Giovanielli American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 417 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract This paper reports an advanced undergraduate laboratory experiment concerning the helicon solid-state plasma wave. Student results are reported. The experiment is performed as an inexpensive dip in a liquid helium storage vessel. The experiment is made possible by the design of a small, superconducting magnet. The magnet is capable of attaining 18 kG and costs about $25. The whole experiment can be built by students in a week's time. When the experiment is completed, the student not only understands helicon propagation but also understands the use of the helicon to measure magnetoresistance and Hall coefficients in pure metals.

Select this Article		Relations among Systems of Electromagnetic Equations Chester H. Page American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 421 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract The equations of electromagnetism, whether written in the electrostatic, electromagnetic, or symmetric system, whether in rationalized or nonrationalized form, express an invariant set of physical relationships. The same set of letter symbols is employed in each, system of equations; these symbols represent related, but different, quantities in the various systems. The relationships among corresponding symbols are given and applied to precise statements about the relation between the oersted and the ampere per meter, the abampere and the ampere, etc.

Select this Article		Experiments with Cholesteric Liquid Crystals James L. Fergason American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 425 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract The following set of experiments was designed for students just beginning to study cholesteric liquid crystals. It contains all of the information on materials and apparatus needed to perform thermal mapping. Wherever possible, materials which are readily available have been chosen. The experiments progress, each one somewhat more difficult than the preceding. No attempt has been made to give an outline of the properties of liquid crystal phases, but the reader is referred to A. Saupe's review article [Angew. Chem. Internat. Edit. 7, No. 2, 97 (1968)] on the subject.

SECTION LISTING

BROWSE VOLUMES

Apr 1970

Volume 38, Issue 4, pp. 407-553

Your Recent History

Recently Viewed

Find articles by AUTHORNAME

Select this Article		Laser Mode Structure Experiments for Undergraduate Laboratories Richard A. Phillips and Robert D. Gehrz American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 429 \| Cited 1 time Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract Experiments dealing with laser mode structure are presented which are suitable for an upper division undergraduate laboratory. The theory of cavity modes is summarized. The mode structure of the radiation from a helium-neon laser is measured by using a photodiode detector and spectrum analyzer to detect intermode beating. Off-axial modes can be visually detected in the expanded laser beam and their presence correlated with signals displayed on the spectrum analyzer in agreement with the theory.

Select this Article		The Virial Theorem and the Equation of State of a Two-Dimensional Plasma G. Knorr American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 433 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract The virial theorem is used for an elementary derivation of the exact equation of state of a two-dimensional plasma.

Select this Article		I Am Curious (Transport Coefficients) E. A. Mason, J. R. Dorfman, and Robert Zwanzig American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 435 \| Cited 2 times Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract Some aspects of the kinetic theory of transport coefficients are discussed in terms of simplified models. These models are a gas of one-dimensional rods and a gas of d-dimensional rigid parallel “cubes.” The collision process is taken to be such that two molecules exchange velocities upon collision. For these models the elementary mean-free-path results are exact, up to an unknown factor of order unity appearing in a correction term.

Select this Article		A Reformulation of Newtonian Dynamics C. Gregory Hood American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 438 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is postulated that all dynamical laws must be formulated in terms of variables measured relative to interacting particles. This implies that the two-particle system is the fundamental interaction unit. When this postulate is applied to Newtonian mechanics, a radically new conceptual structure is revealed. The two major changes which result are the absence of the law of inertia and a broadening of the space and time invariance to include accelerated observers. Although energy and angular momentum remain conserved in this reformulation, the usual linear momentum theorem does not appear. It is further shown that the theory can be expressed in the Lagrangian and Hamiltonian formalisms in a straightforward manner. Finally, applications are made to several simple two-body and three-body systems which demonstrate that many-particle interactions can be formulated without reference to the dynamics of a single particle.

Select this Article		Absorption and Emission of Energy at Electron Cyclotron Resonance S. C. Bloch, H. R. Brooker, and G. J. KeKelis American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 443 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract Experiments are described in which the absorption and emission of energy at and near electron cyclotron resonance may be studied with simplified equipment. The magnetic field is measured by electron spin resonance, thus bringing out aspects of spin as well as orbital angular momentum; the magnetic field may also be measured by the radius of the electron orbit, rendered visible by low-pressure hydrogen. It is observed that, in a gas-focused electron beam tube, the frequencies of maximum electron cyclotron resonance absorption and emission (as determined by the zero crossing of the derivative of the line shape) are generally different from the frequency of electron spin resonance, and the frequency shifts are functions of electron beam current. The line shapes are asymmetric and are also functions of beam current. These effects are tentatively identified with plasma effects in the gas-focused beam.

Select this Article		A Progress Report on Open-End Laboratories John I. Shonle American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 450 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		How Good Is the Hartree-Fock Approximation? II. The Case of Closed Shells A. Calles and M. Moshinsky American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 456 \| Cited 1 time Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract In the present paper, we analyze the problem of an arbitrary number of particles A in a harmonic-oscillator common potential interacting through a harmonic-oscillator force. The particles have spin ½ and obey Fermi statistics. The exact lowest eigenstate and energy are derived for values of A corresponding 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.

Select this Article		Explicit Construction of Unitary Operators in Nonrelativistic Quantum Mechanics Choi-Lai Chan American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 468 \| Cited 1 time Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		One-Dimensional Atom James J. Klein American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 471 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		Thermoelectric Power Experiment for the Advanced Laboratory Thomas B. Greenslade, Jr. American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 480 \| Cited 1 time Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		Circuit Response Using Fourier Series with Experimental Verification H. W. Jones and J. S. Wallingford American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 507 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		Position Expectation Values for an Electron in an Infinite Tilted Well Noble M. Johnson and John N. Churchill American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 487 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		The Merry-Go-Round and Schwarzschild Coordinates: A Comparison B. E. Laurent American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 492 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract The behavior of the Schwarzschild metric inside the gravitational radius is compared to the behavior of the flat space metric in rotating coordinates when r_ω > 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.

Select this Article		Euler Potentials David P. Stern American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 494 \| Cited 13 times Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		Electromagnetic Momentum of Charged Particles Jack Cohn American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 502 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract 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.

Select this Article		Energy Levels of the Hydrogen Atom as a Relativistic Clock-Retardation Effect? J. Dorling American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 510 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is proven that the energy level, according to the Dirac equation, of any stationary state of the hydrogen atom can be written in the form , where m₀ is the electron-rest mass, β is the Dirac-β operator, v is the instantaneous electron velocity in the corresponding orbit in Sommerfeld's relativistic old quantum theory, ν is an “electron apparent frequency” satisfying , and 〈〉 denotes expectation value or time-average value, as appropriate. In spite of the physically suggestive character of this result, it is argued on theoretical grounds that it must be regarded merely as an interesting mathematical accident.

Select this Article		A “Derivation” of Maxwell's Equations Elliott Krefetz American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 513 Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract Herein is presented a student-teacher oriented examination of how one might arrive at Maxwell's equations via a number of reasonable assumptions.

Select this Article		Coherent States in Superfluids: The Ideal Einstein-Bose Gas James R. Johnston American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 516 \| Cited 3 times Online Publication Date: Jul 2005 Full Text: \| Download PDF
	+ -	Show Abstract It is argued that the grand canonical ensemble is not appropriate for describing local properties of a closed system when the system has off-diagonal long-range order over distances of the order of the dimensions of the system (e.g., when there is a condensation into a single-particle state). It is shown that the local dispersion in number in the condensed part of an ideal Einstein-Bose gas is “small” (appropriate to a Poisson distribution), contrary to the usual result obtained using the grand canonical ensemble. This leads to an approximation in which the condensed part of the system is represented locally by a coherent state. It is further argued that these considerations serve as a rationale for breaking gauge symmetry whereas the usual arguments (based on analogy with ferromagnetism) are not appropriate.

Select this Article		Instructional Uses of the Computer: The Harmonic Oscillator in APL Mary F. Gourley American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 529 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Realistic One-Dimensional Example of the Failure of Lattice Dynamics in the Harmonic Approximation S. B. Trickey American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 529 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		A Simple Laboratory Experiment for Studying the Compton Shift H. Sanjeevaiah, S. Gopal, P. Venkataramaiah, and B. Sanjeevaiah American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 530 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Trouble with a Ballistic Pendulum J. Strnad American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 532 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Some Observations on Variable-Geometry Phase Methods of Measuring Sound Wavelength I. C. Romer, Jr. American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 534 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		The Double-Simple Pendulum Problem S. M. Lee American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 536 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Experimental Determination of Moments of Inertia by the Bifilar Pendulum Method John W. Then and Kang-rong Chiang American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 537 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		The Dimensionality of Time J. Dorling American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 539 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Period of Low Orbits R. H. Good American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 540 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Utilizing Automatic Balances for Poggendorff's Experiment on the Second Law of Motion L. Cintra do Prado American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 541 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		A Simple Calculation Concerning Electron Shake-Off during Internal Conversion E. J. Seykora and A. W. Waltner American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 542 \| Cited 1 time Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Jaki on Goethe Otto Blüh American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 544 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable

Select this Article		Re: “Jaki and Goethe” Stanley L. Jaki American Journal of Physics -- April 1970 -- Volume 38, Issue 4, pp. 545 Online Publication Date: Jul 2005 Full Text: \| Download PDF
		Abstract Unavailable