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Full-Text Articles in Physical Sciences and Mathematics

Wave Properties Of Light Jan 1975

Wave Properties Of Light

Calculus-Based General Physics

How do Polaroid sunglasses reduce glare? What evidence is there for an expanding universe? You will learn the answer to these two questions by considering some properties of light. Gamma rays, x rays, light (ultraviolet, visible, and infrared) and radio waves are all forms of electromagnetic radiation and therefore share the same basic properties as mentioned in this module and the module Maxwell's Predictions. The basic difference among these types of electromaonetic radiation is their wavelengths or frequencies.


Vector Multiplication Jan 1975

Vector Multiplication

Calculus-Based General Physics

How much is A times B? This is a simple question to answer when A and B represent scalars; however, when A and B represent vectors, the answer is not obvious. In fact, on the face of it, one cannot even say whether the result should be a scalar or a vector!

Several different definitions of vector multiplication have been found useful in physics; in this module you will study two types: the scalar and vector products. Just to sharpen your interest, we point out that the vector product has the strange but useful property that A × B = …


Work And Energy Jan 1975

Work And Energy

Calculus-Based General Physics

Energy is much in the news lately. The term "energy" usually refers to the inherent ability of a material system, such as a person, a flashlight battery, or rocket fuel, to bring about changes in its environment or in itself. Some common sources of energy are the fuel used to heat hot water, the gasoline that propels a car, the dammed water that drives the turbine in a hydroelectric plant, and the spinning yo-yo that can climb up its own string. Inanimate energy sources are of central importance in raising the standard of living of mankind above the subsistence level. …


Temperature, Heat, And Thermodynamics: First Law Jan 1975

Temperature, Heat, And Thermodynamics: First Law

Calculus-Based General Physics

How can we keep track of energy as it is transferred from one system to another? How can we calculate the amount of internal energy -- a quantity that seems to be hidden within the very "guts" of matter? Further, what is the difference between temperature and heat, and between heat and work?

This module focuses on the first of two central thermodynamic principles: the conservation of energy, or, as it is sometimes called, the first law of thermodynamics. The second basic principle, which deals with the inevitable increase of a quantity called entropy, is the subject of another module …


Sound Jan 1975

Sound

Calculus-Based General Physics

We, much more than our ancestors, are constantly being bombarded by sound. We hear, and are more or less aware of, music, air hammers, television sets, jet planes, conversation, engines, sirens, etc., throughout the day. A sophisticated audio industry tries to improve the quality of musical sound. At the other end of the quality scale, noise pollution is a serious concern, which probably affects our lives more than we realize.

In order to deal with sound, we should have some idea of what it is. What factors determine whether a sound is pleasing or grating? How is sound transmitted? How …


01 Content And Prerequisite Description: Module Sequence/Roadmap With Links Jan 1975

01 Content And Prerequisite Description: Module Sequence/Roadmap With Links

Calculus-Based General Physics

What is the proper order to address the topics in the STUDY MODULES FOR CALCULUS-BASED GENERAL PHYSICS ? Do you need to master "A" before moving on to "B"?

These are prerequisite charts and suggested sequences for study modules of the Calculus-Based Physics Personalized System of Instruction:

I. Mechanics, Sound, Heat

II. Electricity, Magnetism, Light

Each "road map" is linked to the texts of the modules in this repository.


Collisions Jan 1975

Collisions

Calculus-Based General Physics

If you have ever watched or played pool, football, baseball, soccer, hockey, or been involved in an automobile accident you have some idea about the results of a collision. We are interested in studying collisions for a variety of reasons. For example, you can determine the speed of a bullet by making use of the physics of the collision process. You can also estimate the speed of an automobile before the accident by knowing the physics of the collision process and a few other physical principles. Physicists use collisions to determine the properties of atomic and subatomic particles. Essentially, a …


Applications Of Newton's Laws Jan 1975

Applications Of Newton's Laws

Calculus-Based General Physics

Perhaps at some time you have had occasion to swing a massive object at the end of a rope. Maybe you have watched a parent swing a child around by his outstretched arms or have been fortunate enough to watch an athlete throw the hammer. But all of you have heard or watched an automatic washer go through a spin-dry cycle. How was this spinning drum with holes in its periphery able to speed up the "drying" process? The clothes were too large to pass through the holes in the drum and were "held" in a circular path but the …


Direct-Current Circuits Jan 1975

Direct-Current Circuits

Calculus-Based General Physics

One way to help you understand a new phenomenon is to show you that it is like something that you are already familiar with. This method is used very frequently in physics, e.g., the electric field is like the gravitational field. This module will introduce you to a simple class of RC circuits in which there are currents, charges, and voltages that decay exponentially. This may be your first detailed study of exponential decay, but it is like (analagous to) radioactive decay, Newton's law of cooling, the final depletion of a natural resource, the decrease in atmospheric pressure with altitude, …


Electric Fields And Potentials From Continuous Charge Distributions Jan 1975

Electric Fields And Potentials From Continuous Charge Distributions

Calculus-Based General Physics

Too bad! In case you have not realized it, not all charges come packaged as points, spheres, infinite cylinders, or infinite planes. Ah, if only it were so: Life would be much easier from a calculational viewpoint, although somewhat limited in geometrical options. But then, mechanics would be simpler if only constant accelerations were observed in nature ... Not to mention centers of mass; moments of inertia, etc.; all would be considerably simpler to calculate in that wonderful world of point masses, constant accelerations, massless strings, and frictionless boards.

Once again calculus is needed to assist us in analyzing and …


Equilibrium Of Rigid Bodies Jan 1975

Equilibrium Of Rigid Bodies

Calculus-Based General Physics

Most of the objects that one sees are in a state of equilibrium, that is, at rest or in a state of uniform motion. Many man-made structures are designed to achieve and sustain a state of equilibrium, and this, in turn, sets requirements to the materials (their sizes and shapes) that can be used. This module will give you some practice in analyzing the forces that result in equilibrium. From this analysis, if you are given the values of an appropriate set of forces you can find the remaining ones. On the other hand, in designing a stable system you …


Inductance Jan 1975

Inductance

Calculus-Based General Physics

Anyone who has ever grabbed an automobile spark-pluq wire at the wrong place, with the engine running, has an appreciation of the ability of a changinq current in (part of) a coil of wire to induce an emf in the coil. What happens is that the breaker contacts open, suddenly interrupting the current, and causing a sudden large change in the magnetic field through the coil; according to Faraday's law, this results in a (large) induced emf. In general, the production of an emf in a coil by a changing magnetic field due to a current in that same coil …


Impulse And Momentum Jan 1975

Impulse And Momentum

Calculus-Based General Physics

You have already learned that you stub your toe harder trying to kick larger masses. Now imagine another unpleasant activity: catching a bowling ball. This gets harder to do as the ball is dropped from higher places. The difficulty depends both on the ball's mass and its velocity just before you apply the stopping force. This force can be applied in different ways. Any winner of an egg-throwing contest will tell you the way to stop an object with the least force is to spread the stopping process out over a maximum time.

This module will develop the above "folk …


A Guide To What, How, Why And Why Not Of Psi, Vernon Williams, Robert Fuller, David Joseph Jan 1975

A Guide To What, How, Why And Why Not Of Psi, Vernon Williams, Robert Fuller, David Joseph

Personalized System of Instruction (PSI), or Keller Plan, Materials

The production and distribution of the film, Personalized System of Instruction: An Alternative, © 1973, by the Instructional Media Center of the University of Nebraska Lincoln was met with considerable interest among academics in the USA. A one time the film lending library had 24 copies of the film that were is almost continuous distribution in the early 1970s.

The film lead viewers to ask many questions and the Instructional Media Center got many requests for additional information. In response to that need, Vernon Williams of the Teaching and Learning Center and Professors Robert Fuller and David Joseph of …


Response Of Nuclear Emulsions To Ionizing Radiations, Robert Katz, F. E. Pinkerton Jan 1975

Response Of Nuclear Emulsions To Ionizing Radiations, Robert Katz, F. E. Pinkerton

Robert Katz Publications

Heavy ion tracks in Ilford K-2 emulsion are simulated with a computer program that makes use of the delta-ray theory of track structure, and the special assumption that the response of the emulsion to gamma-rays is 8-or-more hit. The Ilford K-series of nuclear emulsions is produced from a parent stock called K.0 emulsion, sensitized to become K.1 to K.5, and desensitized to become K–1 to K–3. Our simulations demonstrate that the emulsions K.5 through K.0 to K-1 are 1-or-more hit detectors, while K-2 is an 8-or-more hit detector. We have no data for K-3 emulsion. It would appear that emulsions …


Temperature-Dependence Of Electron Mean Free Paths In Tungsten, Paul D. Hambourger Jan 1975

Temperature-Dependence Of Electron Mean Free Paths In Tungsten, Paul D. Hambourger

Physics Faculty Publications

No abstract provided.


Surface Electromagnetic Waves On Layered Systems With Damping, C. A. Ward, Ralph William Alexander, Robert John Bell Jan 1975

Surface Electromagnetic Waves On Layered Systems With Damping, C. A. Ward, Ralph William Alexander, Robert John Bell

Physics Faculty Research & Creative Works

The Dispersion Curves, Propagation Distances, and Poynting Vectors of Surface Electromagnetic Waves Propagating on a System of Cu-Cu2O-Air with Variable Film Thickness Have Been Calculated using the Full Dispersion Realation Including Damping. Double-Dip Structure in the Propagation Distance for Intermediately Thick overlayers, the Shifting of One Dip Below ΣTO, and the Presence of the Other Dip at ΣLO Are Explained in Terms of Features of the Dispersion Curve. the Complete Poynting-Vector Calculations Show that Predictions of Field Bunching at ΣLO Are Probably in Error. © 1975 the American Physical Society.


Double Reflection Dips From Grating Ruled Semiconductors, L. F. Teng, Ralph William Alexander, Robert John Bell, B. Fischer Jan 1975

Double Reflection Dips From Grating Ruled Semiconductors, L. F. Teng, Ralph William Alexander, Robert John Bell, B. Fischer

Physics Faculty Research & Creative Works

The Double Reflectivity Dips, Previously Observed by Fischer Et Al. and Anderson Et Al., Which Appeared in the Reflection Spectra of Grating Surfaces On, the Te‐doped Semiconductors GaAs and InSb Around Both the Plasmon and Phonon Frequencies Have Been Measured in More Detail. in the Plasmon Region, Several Possible Explanations of the Phenomenon Are Discussed, But the Favored Explanation Involves Surface Damage. a Simple Two‐region Reflectivity Equation Checked with a Rigorous Grating Theory is Proposed and is Shown to Fit the Data Well. Copyright © 1975 WILEY‐VCH Verlag GmbH & Co. KGaA


Multimedia Dispersion Relation For Surface Electromagnetic Waves, C. A. Ward, K. Bhasin, Robert John Bell, Ralph William Alexander, I. Tyler Jan 1975

Multimedia Dispersion Relation For Surface Electromagnetic Waves, C. A. Ward, K. Bhasin, Robert John Bell, Ralph William Alexander, I. Tyler

Physics Faculty Research & Creative Works

We Have Derived a General, N-Media Dispersion Relation for Surface Electromagnetic Waves Propagating on Isotropic Layers with Complex Dielectric Functions. the Equation is Presented in a Convenient, Compact Form for Ease of Application. Copyright © 1975 American Institute of Physics.


Metamagnetic Behavior Of Linear Chain Pyridine Compounds: Co(Pyridine)2Cl2, Fe(Pyridine)2Cl2, Fe(Pyridine)2(Ncs)2 And Ni(Pyridine)2Cl2, S. Foner, R. B. Frankel, W. M. Reiff, B. F. Little, G. J. Long Jan 1975

Metamagnetic Behavior Of Linear Chain Pyridine Compounds: Co(Pyridine)2Cl2, Fe(Pyridine)2Cl2, Fe(Pyridine)2(Ncs)2 And Ni(Pyridine)2Cl2, S. Foner, R. B. Frankel, W. M. Reiff, B. F. Little, G. J. Long

Physics

Magnetic phase transitions in the pyridine (pyr) compounds Co(pyr)2Cl2, Fe(pyr)2Cl2, Fe(pyr)2(NCS)2 and Ni(pyr)2Cl2 have been observed at applied magnetic fields of not, vert, similar0.7, 0.7, 1.1 and 2.7 kG respectively. These low field phase transitions are observed in the Fe and Ni compounds at T = 4.2 K, and in the Co compound at T < 3K, and are consistent with metamagnetic behavior. Magnetic saturation is not achieved in any of these compounds for fields of 60 kG, reflecting high anisotropy.


Auroral Energy Input From Energetic Electrons And Joule Heating At Chatanika, Vincent B. Wickwar, M J. Baron, R D. Sears Jan 1975

Auroral Energy Input From Energetic Electrons And Joule Heating At Chatanika, Vincent B. Wickwar, M J. Baron, R D. Sears

All Physics Faculty Publications

With the incoherent scatter radar at Chatanika, Alaska, a wide variety of measurements can be made related to the ionosphere, magnetosphere, and neutral atmosphere. A significant parameter is the amount of energy transferred from the magnetosphere into the ionosphere and neutral atmosphere during periods of auroral activity. In this report we examine a procedure whereby the incident energy flux of auroral electrons is ascertained from radar measurements. As part of the process we compare radar-determined fluxes with those ascertained from simultaneous photometric observations at 4278 Å. The fluxes obtained by both techniques had similar magnitudes and time variations. If we …


The Effect Of The Gradient-Drift Term On Type I Electrojet Irregularities, D. T. Farley, Bela G. Fejer Jan 1975

The Effect Of The Gradient-Drift Term On Type I Electrojet Irregularities, D. T. Farley, Bela G. Fejer

Bela G. Fejer

We hypothesize that type 1 VHF radar echoes can only be observed when the electrojet plasma is linearly unstable at half the radar wavelength and that further, for reasons not yet understood, the phase velocity of the unstable waves always corresponds to the threshold conditions for instability, even when the destabilizing forces (electron drift and plasma density gradient) exceed the threshold. This phase velocity, which produces the Doppler shift of the radar echoes, is usually close to the ion acoustic velocity of the medium but can differ from it to some extent because of the effect of the density gradient. …


Vertical Structure Of The Vhf Backscattering Region In The Equatorial Electrojet And The Gradient Drift Instability, Bela G. Fejer, D. T. Farley, B. B. Balsley, R. F. Woodman Jan 1975

Vertical Structure Of The Vhf Backscattering Region In The Equatorial Electrojet And The Gradient Drift Instability, Bela G. Fejer, D. T. Farley, B. B. Balsley, R. F. Woodman

Bela G. Fejer

Radar measurements made with high spatial resolution and large dynamic range at the Jicamarca Radar Observatory near the time of reversal of the electrojet current provide further proof that the gradient drift instability is in fact responsible for the type 2 irregularities. Echoes are received over a much wider range of altitudes at night than during the day partly because of the change in character of the background electron density profile and partly because of recombination effects, which can be important during the day. It is also shown that one must be cautious, particularly at night, in associating the mean …


Oblique Vhf Spectral Studies Ofthe Equatorial Electrojet, Bela G. Fejer, D. T. Farley, B. B. Balsley, R. F. Woodman Jan 1975

Oblique Vhf Spectral Studies Ofthe Equatorial Electrojet, Bela G. Fejer, D. T. Farley, B. B. Balsley, R. F. Woodman

Bela G. Fejer

A new narrow-beam antenna at the Jicamarca Observatory permits oblique (zenith angle, 25°) radar spectral studies of the electrojet with an altitude resolution down to 1.1 km. Only daytime observations are possible presently, however. The general altitude variations in spectral shape observed are consistent with linear instability theory, if the effect of recombination is included. The height at which the mean Doppler shift of the echo maximizes, however, is about 4 km higher than one would expect on the basis of electrojet models. An increase in the assumed collision frequency would remove the discrepancy. Other data presented strongly suggest that …


Inclusion Of Rectangular And Triangular Geometries In The Space-Dependent Kinetics Code, Fx2, Ted Perry Jan 1975

Inclusion Of Rectangular And Triangular Geometries In The Space-Dependent Kinetics Code, Fx2, Ted Perry

Undergraduate Honors Capstone Projects

The computer code FX2 is used to model liquid-metal fast-breeder reactors now being developed by the U. S. Atomic Energy Commission. These reactors differ from thermal reactors in that they have no moderator material in their cores and thus operate at mean neutron energies of 100 keV or more as opposed to neutron energies of less than 1 keV for thermal reactors. Also these reactors have the advantage that as a consequence of the high neutron energies, these reactors can be used to "breed" their own fuel: enriched 238U placed in the core is changed into plutonium which can …


Erratum: Multimedia Dispersion Relation For Surface Electromagnetic Waves. (The Journal Of Chemical Physics (1975) 62 (1674)), C. A. Ward, K. Bhasin, Robert John Bell, Ralph William Alexander, I. Tyler Jan 1975

Erratum: Multimedia Dispersion Relation For Surface Electromagnetic Waves. (The Journal Of Chemical Physics (1975) 62 (1674)), C. A. Ward, K. Bhasin, Robert John Bell, Ralph William Alexander, I. Tyler

Physics Faculty Research & Creative Works

No abstract provided.


Biquadratic Exchange And First-Order Ferromagnetic Phase Transitions, Harry A. Brown Jan 1975

Biquadratic Exchange And First-Order Ferromagnetic Phase Transitions, Harry A. Brown

Physics Faculty Research & Creative Works

We have calculated some properties of a ferromagnet using a Heisenberg Hamiltonian with a biquadratic exchange term added. The constant-coupling approximation was employed. If the strength of the biquadratic exchange relative to the bilinear is given by a dimensionless parameter α, there is a critical value αc at which the phase transition changes character from second order for αα>αc. The spontaneous magnetization, the exchange energy, and the spin-correlation function show discontinuous jumps at α=αc and unstable behavior for α>αc. © 1975 The American Physical Society.


Use Of The Psi Technique In Prerequisite Courses, John T. Park, William R. Snow Jan 1975

Use Of The Psi Technique In Prerequisite Courses, John T. Park, William R. Snow

Physics Faculty Research & Creative Works

An engineering physics course, in which the Personalized System of Instruction (PSI) technique has been used, has been designed to meet the requirements that all of a prescribed list of subjects be covered and that the course be completed within a single semester. The course was modified so that it has two levels of mastery for each unit: a passing level and a complete mastery level. All students were required to reach a passing level of mastery on all of the required material. Grades were assigned according to the number of complete mastery level examinations passed. It was found that …


The Use Of Surface Electromagnetic Waves To Measure Materials Properties, Ralph William Alexander, Robert John Bell Jan 1975

The Use Of Surface Electromagnetic Waves To Measure Materials Properties, Ralph William Alexander, Robert John Bell

Physics Faculty Research & Creative Works

An Elementary Introduction to Surface Electromagnetic Waves (SEW) is Presented. the Emphasis is on Those Features of SEW Which Make Them Useful for Measuring Optical Properties of Thin Layers on Metals. the So-Called Two-Prism Technique for Making Such Measurements is Discussed, Some Preliminary Experimental Results Are Given, and Some Possible Applications Are Presented. © 1975.


Excitation Of Atomic Hydrogen To The N=2 States By 15-200-Kev Protons, John T. Park, J. E. Aldag, J. M. George Jan 1975

Excitation Of Atomic Hydrogen To The N=2 States By 15-200-Kev Protons, John T. Park, J. E. Aldag, J. M. George

Physics Faculty Research & Creative Works

Cross sections for the process H+ + H H+ + H* (n=2) are determined from the energy-loss spectra of 15-200-keV protons. After normalization at 200 keV to the Born approximation, the maximum value (1.07 x 10-16 cm2 at 60 keV) lies below close-coupling calculations and above Glauber-approximation calculations. The agreement with low-energy (5-30-keV) data of others is very good. © 1975 The American Physical Society.