摘要:

This paper describes a scenario for an upper‐level undergraduate laboratory in which the students take roles as staff members in a contract research company, UMR, Inc. Each student is assigned to a role as Senior Scientist, Researcher, or Technician based on their letter of application, resume, and personal interview. Students are assigned to research groups and participate in a project feasibility study and in writing the resulting proposal. The assembly of apparatus, data taking, and data analysis proceed as in the usual project laboratory. At the end of the semester each student writes a section of the final report and presents a 10‐min technical talk. The instructor and the assisting graduate student assume the roles of President/Chief Consultant and Vice President/Associate Consultant/Stockroom Man, respectively.

ISSN:0002-9505    

DOI:10.1119/1.11179

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

An attempt to survey all of the topics traditionally covered in undergraduate physics courses in one semester, with strong emphasis on everyday phenomena of nature, is described. In order to compress a survey course in physics into one semester, a number of unusual techniques were used and are described. A point was also made, during the course, to debunk certain brands of pseudoscience popular among college students, with mixed success. The course was aimed at the mass audience of nonscience majors having only a one‐semester general sciences degree requirement, used no details of mathematics, and relied heavily on lecture demonstrations, slides, film‐loops, and overhead projector artwork.

ISSN:0002-9505    

DOI:10.1119/1.11107

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

Non‐trivial but elementary numerical examples of basic mechanics are lacking in most introductory textbooks. This paper gives several very simple examples which relate to numbers for which many students already have some intuition. In particular, we estimate the speeds of running, cycling, and walking, the length of a good broad‐jump, the heights of a polēvault and a vertical high jump from rest, and the time for running up a flight of stairs. These estimates and the observed numbers are found to match rather well.

ISSN:0002-9505    

DOI:10.1119/1.11173

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

It is pointed out that there is a close relationship between the energy efficiency ratio (EER) of an air conditioner unit and the coefficient of performance (COP) of its refrigeration cycle. This connection helps to bridge the gap between pure thermodynamics and practical energy‐related problems. In this spirit, two other efficiency parameters, the total COP and total EER, measured relative to the energy extracted by a primary energy source (e.g., a fossil fuel), are defined. A comparison of the actual total COP (or total EER) relative to its maximum allowed value, consistent with the second law of thermodynamics, leads to an estimate for air conditioners of the recently proposedsecondlawefficiency.

ISSN:0002-9505    

DOI:10.1119/1.11174

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

In order to understand the fundamental properties of a star in radiative equilibrium, a simplified model is introduced which yields relations for physical quantities by elementary methods. In particular, the dependence of these quantities on the parameters of the star and on the fundamental constants of nature is exhibited. Numerical evaluation of these relations is in good agreement with observation and with more elaborate calculations.

ISSN:0002-9505    

DOI:10.1119/1.11176

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

We present the outline of a new course designed to teach the physical principles underlying biological measurements. This course, intended for undergraduate and first‐year graduate students who have taken noncalculus introductory physics, is primarily aimed at biological science and biophysics majors interested in research careers in those fields. The course consists of lectures and demonstrations on a series of topics including NMR, ultracentrifugation, electronics, and optical and electron microscopy. Our intent is to teach the student the principles underlying the measurements they perform in their laboratories and the uses and limitations of the various techniques.

ISSN:0002-9505    

DOI:10.1119/1.11177

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

The electromagnetic field within a waveguide is described in terms of an infinite discrete set of variables which permits the application of the formalism of quantum mechanics. The quantized field exhibits potential energy which depends on the structure of the guide and the mode of the field but not on the frequency. The radiant energy experiences a compression during the transition from one guide into another one of smaller cross section.

ISSN:0002-9505    

DOI:10.1119/1.11178

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

The vibrations of a mass connected to fixed supports by two ’’ideal’’ Hooke’s law springs are considered. Although the longitudinal vibrations of this system are always harmonic, the transverse vibrations are, in general, anharmonic even though both springs obey Hooke’s law. In fact, it is found that as the supports are brought together, allowing the springs to become slack, the purely transverse motion becomes strongly anharmonic even for small displacements of the mass from its equilibrium position. This independent oscillator model seems to possess many of the properties of an ion in a crystal undergoing a soft mode activated transition. We suggest that the model may serve as a useful conceptual starting point in the study of these transitions. Some particular solutions of the dynamical equations for the model system are investigated in detail.

ISSN:0002-9505    

DOI:10.1119/1.11180

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

An experimental arrangement which can be used for double exposure holographic interferometry is described. We have used this setup to measure a series of rotations which range from 4×10−5to 5×10−4rad. The result is in excellent agreement with theory.

ISSN:0002-9505    

DOI:10.1119/1.11181

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP

摘要:

The usual solution of the diffusion equation gives inaccurate results for short diffusion times for displacements which are relatively large compared to the maximum range of the diffusion. A method is proposed for solving the diffusion equation by a random‐walk approximation technique which utilizes the appropriate generating functions and the complex integration method of steepest descent. The power of the method is illustrated for a one‐dimensional random walk (SRW) and for physical situations in which the elementary diffusion process is governed by a normal or a rectangular probability distribution. Formulas for higher approximations applicable to any probability distribution are also derived. The method, which can also be applied to two and three dimensions, is capable of yielding high accuracy for the diffusion solution over the entire diffusion domain.

ISSN:0002-9505    

DOI:10.1119/1.11101

出版商:American Association of Physics Teachers    

年代:1978

数据来源: AIP