摘要:

This nonquantitative electronic circuit exercise is suitable for beginning or advanced students. The minimum operating time of a binary counter is measured in microseconds by means of a twin pulse generator. The operating cycle of the latter is studied in terms of its oscilloscope patterns.

ISSN:0002-9505    

DOI:10.1119/1.1933573

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

A simple but general treatment of reflection and refraction at spherical surfaces is based on properties of nodal points and the specification of wave fronts by their convergences. Rules for the location and description of images are justified and extended to the images formed by thin lenses, the positions of whose nodal points make apparent an analogy with single refracting surfaces. The formula for the change in convergence of a wave front proceeding in a homogeneous and isotropic medium is applied to describe the images of axial objects, to derive Newton's relation in generalized form, and to consider refraction by separated refracting surfaces of unspecified powers. Solutions to five numerical problems, obtained by methods advocated in the paper, are appended.

ISSN:0002-9505    

DOI:10.1119/1.1933574

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

A dynamic model to illustrate atomic and nuclear magnetic phenomena is described. An airdriven spinning magnetic dipole placed in a magnetic field exhibits a Larmor precession whose dependence on magnetic and gravitational parameters can be demonstrated. An ac magnetic field of variable frequency permits a visual demonstration of magnetic resonance.Data obtained from the precession experiments can be used for a precise determination of the earth's magnetic field.

ISSN:0002-9505    

DOI:10.1119/1.1933575

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Inspection of the equations of compressible hydrodynamics in one dimension shows that the steady state may possess a discontinuity in the flow variablesu,p, ρ. From this there arises the possibility of constructing a dimensionless parameter characterizing shock strengths. Its relations with other shock parameters are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1933576

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

A report is presented of a study made primarily in the Southern States to determine what the certification requirements for teachers of high school physics are and what some college physics teachers think they should be; to determine what special undergraduate and graduate programs of study for those preparing to teach or already teaching high school physics are provided by colleges; and also to discover to what extent college physics departments are cooperating with high school physics departments, by loaning equipment, giving assistance to science clubs, presenting demonstration lectures at high school assembly programs, and discussing opportunities for a career in physics with high school seniors.

ISSN:0002-9505    

DOI:10.1119/1.1933577

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Suggestions are made for restoring to elementary laboratory work the sense of adventure and intellectual excitement which has to a considerable extent been displaced by the notion that “efficient” and assembly-line speed of instruction is desirable.

ISSN:0002-9505    

DOI:10.1119/1.1933578

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

This paper describes a method for rendering visible the parabolic velocity distribution in laminar flow through a conduit. An opaque cloud having the shape of a thin line disposed along a pipe diameter is created by electrochemical means. This line is distorted into a parabola by the motion of the fluid.

ISSN:0002-9505    

DOI:10.1119/1.1933579

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

The requirements that must be satisfied by a nonrelativistic theory of electron spin are examined, and it is shown, with the aid of elementary spinor theory, that these requirements can be met by a geometric scheme whose main operation is the reflection of spinors in an axis. This yields a kind of picture of electron spin. The analytical formulation of the geometric scheme is developed, and is identical with the Pauli spin theory. The part played by nonstationary spin states in the geometric scheme is discussed.

ISSN:0002-9505    

DOI:10.1119/1.1933580

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Some concepts and ideas of contemporary physics are surveyed in order that a pattern of scientific thought broader and more meaningful than that permitted by strictly technical approach may be achieved.

ISSN:0002-9505    

DOI:10.1119/1.1933581

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP

摘要:

Equations are derived for the steady-state shape of a wire cutting a uniform medium, and some wire shapes are shown. The principal assumption is that any element of length of the wire moves into the medium at a rate proportional to thekth power of the normal force per unit length that the wire exerts on the medium.

ISSN:0002-9505    

DOI:10.1119/1.1933582

出版商:American Association of Physics Teachers    

年代:1953

数据来源: AIP