摘要:

In these experiments numerical integration is used to verify Faraday’s law of induction for the case of an open‐circuit homopolar generator. The computed emfs are compared with experimentally measured values.

ISSN:0002-9505    

DOI:10.1119/1.15076

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

We describe a simple one‐step optical recording geometry for the fabrication of a white light transmission hologram. The arrangement is a modified Leith–Upatnieks off‐axis holographic configuration that yields a wide‐field, deep‐scene rainbow hologram. Detailed recording layout of the hologram and the experimental results are also included.

ISSN:0002-9505    

DOI:10.1119/1.15077

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

A classical formulation of the nonrelativistic Kepler problem in terms of expectation values of powers of the radial coordinateris presented. Perturbations to this problem arising from relativistic corrections to the kinetic and potential energies, multipole moments of the central potential, other confocal orbitals, etc. can be written in terms of powers ofrand thus be accounted for through these expectation values in a simple and pedagogically transparent way. Macroscopic and microscopic examples are treated as special cases of this common formulation.

ISSN:0002-9505    

DOI:10.1119/1.15078

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

An advanced undergraduate laboratory experiment is described which uses a laser, low‐voltage pulser, and a Pöckels‐cell electro‐optical modulator to determine the speed of light using time of flight. Accuracy of about 1/2 % is obtained using a calibrated oscilloscope while an uncertainty of less than 0.2% can be obtained using a time‐to‐analog converter (TAC) and multichannel analyzer (MCA). The experiment is used to illustrate electro‐optical modulators and time‐of‐flight instrumentation.

ISSN:0002-9505    

DOI:10.1119/1.15079

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

Velocity modulation of an electron beam, which is the underlying physical phenomena for various microwave tubes such as klystrons and magnetrons, is interpreted in terms of a water bag model which has its origin in plasma physics. Using this technique, it is possible to estimate the expected amplitude for a velocity‐modulated electron beam.

ISSN:0002-9505    

DOI:10.1119/1.15091

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

We describe an undergraduate plasma physics experiment using an easily constructed and inexpensive apparatus that nevertheless involves the more advanced physics of the interaction between plasma and electromagnetic radiation. The experiment is based on the readily available plasma of a fluorescent lamp. The lamp is placed inside a resonant cavity and the shifts in the frequencies of cavity resonances are used to determine the plasma density as a function of time. We describe a circuit that allows measurements to be made of the decay of the afterglow plasma, and show experimentally determined decay rates and densities that are consistent with the literature on fluorescent lamps and gas discharges.

ISSN:0002-9505    

DOI:10.1119/1.15316

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

Three physical models of the human body’s response to a glucose challenge are presented from the medical literature. Glucose tolerance is evaluated using kinematical techniques, an exponential‐decay analysis, and a damped harmonic‐oscillator model. Each treatment contains material suitable as supplementary topics in physics courses, both introductory and intermediate.

ISSN:0002-9505    

DOI:10.1119/1.15092

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

Using a video camera with a stopwatch feature and a VCR enabled my class to study the effects of air resistance acting on the following pendulum bobs: Ping‐Pong ball, styrofoam spheres, and a brass sphere. We measured the maximum return angle on each swing for a pendulum (L=1 m) released from an angle of 70°. The students wrote a computer program to analyze the data, assuming that the force of air resistance equalscr2v2, wherec=0.87 kg/m3. We found thatcwas larger than this and extracted the force of air resistance acting on the string. As part of the lab project, we also measured the period and position‐versus‐time when a pendulum with a brass bob was released at a large angle.

ISSN:0002-9505    

DOI:10.1119/1.15093

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

The geometry of crumpled paper balls is examined. The analysis stresses some physical, mathematical, and intuitive aspects of the problem, introducing the concept of fractal dimension which underlies many areas of modern physics.

ISSN:0002-9505    

DOI:10.1119/1.15094

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP

摘要:

An experiment has been developed for the intermediate physics laboratory in which the students use a microcomputer to investigate statistics and errors. A multichannel scaler is used to collect distributions of events per unit time from a radioactive source, and the data are stored on computer diskettes. Students write programs to calculate properties such as the mean and standard deviation of each distribution, and combine data sets in various ways in order to investigate how errors (standard deviations) are propagated.

ISSN:0002-9505    

DOI:10.1119/1.15315

出版商:American Association of Physics Teachers    

年代:1987

数据来源: AIP