ISSN:0002-9505    

DOI:10.1119/1.1934046

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

摘要:

It is argued that the correct understanding and teaching of the special theory of relativity are still impaired by a number of specific, widespread misconceptions. To remove these, the relevant definitional, experimental, and philosophical foundations of the kinematics of the theory are made explicit by reference to the following issues: (i) the relativity of simultaneity, which arises, in the first instance,withinasingleGalilean frame, (ii) the principle of the constancy of the speed of light, which rests on threedistinctexperimental facts as well as on an important convention, made possible by a fourth experimental result, (iii) the compatibility of the invariance of the speed of light with theabsenceof a retardation on the part of moving clocks, and the role of that optical principle in the deduction of the Lorentz transformations, (iv) the merits of thead hoccharge against the Lorentz-Fitzgerald contraction hypothesis; the philosophical sources of the difference between Lorentz' and Einstein's interpretations of the transformation equations.

ISSN:0002-9505    

DOI:10.1119/1.1934047

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

摘要:

Many articles and text books have treated acoustic filters from various viewpoints, and acoustic filter experiments have been devised for laboratory courses in acoustics. These experiments frequently point out the analogy between lumped-constant acoustic filters and electrical filters, in order to make use of the many texts and handbooks dealing with electrical filter theory and construction. Although it is clear that electrical filters are designed to operate from a specified source impedance and into a specified load impedance, the laboratory experiments which the author has seen do not apply this requirement to the acoustic filters used. The present article describes an acoustic source with a primarily resistive output impedance, a microphoen assembly which serves as a primarily resistive load impedance and detector, and a low-pass acoustic filter designed to match them. The analogous electrical filter was built, and the performance characteristics of the two filters are compared.

ISSN:0002-9505    

DOI:10.1119/1.1934048

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

摘要:

A new approach to the study of simple harmonic motion is presented. A record is taken of the positions at different times by means of a spark timer. From the limits approached by the average velocities, instantaneous velocities are obtained. From the limits approached by the average accelerations, instantaneous accelerations are obtained. A linear relation shows the direct proportionality between acceleration and displacement. The period of SHM may be determined from the slope of this straight line and compared with the experimental value.

ISSN:0002-9505    

DOI:10.1119/1.1934049

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934051

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934052

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934054

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934055

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934058

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1934059

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP