ISSN:0002-9505    

DOI:10.1119/1.15187

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.15189

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.15191

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.15320

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

United States energy consumption has remained essentially constant at about 80 exajoules/year (75 quads/year) since the oil embargo of 1973–1974, while the GNP in constant dollars has increased by about 30%. This article will discuss the physics behind some of these improvements in end‐use efficiency in such areas as: (i) buildings (scaling laws, ‘‘free‐heat,’’ superinsulated houses, thermal storage in large buildings, off‐peak cooling), (ii) solar energy (passive, photovoltaics), (iii) utility load management (‘‘smart meters,’’ capital recovery fees, voltage control), (iv) appliances (life‐cycle costs, refrigerators), and (v) lighting (isotopic enhancement).

ISSN:0002-9505    

DOI:10.1119/1.15193

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

We demonstrate the existence of strange attractors in a simple dissipative mechanical system, a bouncing ball subject to repeated impacts with a vibrating table.

ISSN:0002-9505    

DOI:10.1119/1.15194

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

Graphical methods showing the relationships among object and image positions, focal length and magnification for geometric optics are extended to the use of Newtonian variables. By defining similar quantities for Gaussian beams, we develop graphical methods to describe the relationships among the parameters specifying Gaussian beams. Examples are included.

ISSN:0002-9505    

DOI:10.1119/1.15199

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

A new suspension/release mechanism for a free‐fall experiment is described. Its design makes it possible to measure time intervals to ±10 μs in free‐fall‐from‐rest experiments. With an overall accuracy of ±0.022%, the different accelerations (in air) of various falling bodies can be determined. Agreement with theory is shown to be very good for the case of spheres. Questions concerning the appropriate drag coefficients applicable are discussed.

ISSN:0002-9505    

DOI:10.1119/1.15200

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

The theory of the classical string and the method of canonical quantization are reviewed. The nonrelativistic string is then quantized using the canonical quantization procedure. A number of properties of quantized strings, such as quantized normal modes of vibration and ground state fluctuations, are discussed. The quantized nonrelativistic string is compared to quantized fields and to the strings in the recent superstring theories. The theory of relativistic strings is reviewed.

ISSN:0002-9505    

DOI:10.1119/1.15201

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

The stellar sky—as seen from the vicinity of a black hole—is discussed as a method to visualize the effects of light deflection. For rotating black holes, spatial axes defining the spherical angles of arriving light rays were defined via the direction of the plumb lines. Some light rays circling a strongly rotating black hole (extreme Kerr black hole) are also shown.

ISSN:0002-9505    

DOI:10.1119/1.15319

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP