Digital Commons Network^™

Physics, Chatper 24: Potential, Henry Semat, Robert Katz

Robert Katz Publications

A positive charge q situated at some point A in an electric field where the intensity is E will experience a force F given by Equation (23-1a) as F = Eq. In general, if this charge q is moved to some other point B in the electric field, an amount of work ΔW will have to be performed. The ratio of the work done ΔW to charge q transferred from point A to point B is called the difference of potential ΔV between these points.

Physics, Chapter 23: The Electric Field, Henry Semat, Robert Katz

Robert Katz Publications

We have previously described the gravitational field as one way of thinking about gravitational forces (Section 6-16). If an object of mass m at rest at a point P experienced a force, we could attribute that force to the presence of the gravitational field. In a similar way we may attribute the force experienced by an electric charge at rest at a point P to the presence of an electric field at that point. From the preceding chapter we recognize that the existence of a force ,on a charged particle is due to the presence of other charged particles in …

Physics, Chapter 22: Electrostatics, Henry Semat, Robert Katz

Robert Katz Publications

One simple phenomenon of electricity was known to the ancients: that when a piece of amber was rubbed, it acquired the property of attracting small pieces of paper and other light particles. Records show that Thales of Miletus (circa sixth century B.C.) knew of this property of amber; the Greek word for amber is elektron, hence the name electricity. There was practically no further development of this subject until about the seventeenth century. Otto von Guericke (1602-1686) of Magdeburg built a large sulphur sphere, which, when rotated about an axis and rubbed with his hand, gave off electric sparks. In …

Physics, Chapter 18: Transfer Of Heat, Henry Semat, Robert Katz

Robert Katz Publications

The methods by which heat is transmitted can be classified into three distinct types known as convection, conduction, and radiation. In any actual case of heat transmission, a combination of these methods may be operating simultaneously, and the principal problem is to determine the rate at which heat flows from the source at higher temperature to the source at lower temperature.

We may distinguish between the three processes of heat transfer by considering whether a medium is required for the transfer of heat, and whether that medium is at rest or in motion. In the process of conduction, …

Physics, Chapter 17: The Phases Of Matter, Henry Semat, Robert Katz

Robert Katz Publications

A substance which has a definite chemical composition can exist in one or more phases, such as the vapor phase, the liquid phase, or the solid phase. When two or more such phases are in equilibrium at any given temperature and pressure, there are always surfaces of separation between the two phases.

In the solid phase a pure substance generally exhibits a well-defined crystal structure in which the atoms or molecules of the substance are arranged in a repetitive lattice. Many substances are known to exist in several different solid phases at different conditions of temperature and pressure. These …

Physics, Chapter 15: Heat And Work, Henry Semat, Robert Katz

Robert Katz Publications

Until about 1750 the concepts of heat and temperature were not clearly distinguished. The two concepts were thought to be equivalent in the sense that bodies at equal temperatures were thought to "contain" equal amounts of heat. Joseph Black (1728-1799) was the first to make a clear distinction between heat and temperature. Black believed that heat was a form of matter, which subsequently came to be called caloric, and that the change in temperature of a body when caloric was added to it was associated with a property of the body which he called the capacity. Later investigators endowed caloric …

Physics, Appendix C, Henry Semat, Robert Katz

Robert Katz Publications

Appendix C: Answers to Odd-Numbered Problems

Physics, Chapter 44: Stable Nuclei, Henry Semat, Robert Katz

Robert Katz Publications

Atomic and nuclear physics are essentially twentieth-century developments, although these had their origins at the close of the nineteenth century. These developments followed two parallel streams, as shown in Figure 44-1, one dealing with the electronic structure of the atom and the other dealing with its nuclear structure. These two streams served to feed each other and were fed by all other branches of physics, but only a few of the more important contributions concerning the nature of radiation, matter, and energy are shown in the figure.

Physics, Chapter 43: X-Rays, Henry Semat, Robert Katz

Robert Katz Publications

The study of the electric discharge through gases led directly to the discovery of x-rays by W. C. Roentgen in 1895. While operating a gas discharge tube, Roentgen observed that a platinum-barium cyanide screen at some distance from the tube fluoresced. He shielded the tube so that no visible radiation could reach the screen, but the fluorescence could still be observed. On interposing various materials between the tube and the screen, he found that the intensity of the fluorescence could be diminished, but that it was not completely obliterated. He interpreted these observations as being due to radiation coming from …

Physics, Chapter 41: Polarized Light, Henry Semat, Robert Katz

Robert Katz Publications

The phenomena of interference and diffraction show that light is propagated as a wave motion, but they do not show whether light is a longitudinal wave or a transverse wave. The fact that the velocity of light is the same as the velocity of radio waves and the radiation of visible light from accelerated electrons, as in a betatron, indicates that light is an electromagnetic wave. We recall from Section 20-9 that a wave can be shown to be transverse if a device can be found which will prevent passage of the wave in one orientation and will allow the …

Physics, Chapter 40: Light As A Wave Motion, Henry Semat, Robert Katz

Robert Katz Publications

Let us recount some of the characteristics of the motion of particles and the propagation of waves, with a view toward analyzing the behavior of light. In accordance with Newton's first law, a particle moves in a straight-line path in the absence of external forces. Thus we might infer, as Newton suggested, that light is composed of particles, and that, in a continuous medium, there is no deflecting force on the light particles. At the interface between two media, light may be propagated in a straight line parallel to the interface. Thus even at an interface there is no force …

Physics, Chapter 38: Mirrors And Lenses, Henry Semat, Robert Katz

Robert Katz Publications

A spherical mirror consists of a small section of the surface of a sphere with one side of the surface covered with a polished reflecting material, usually silver or aluminum. If the outside, or convex surface, is silvered, we have a convex mirror; if the inside, or concave surface, is silvered, we have a concave mirror, as shown in Figure 38-1. Most mirrors used commercially are made of glass, with the rear surface silvered and then coated with a layer of paint or lacquer for protection. Mirrors for astronomical telescopes (')f other accurate scientific work are provided with a reflective …

A Study Of Background In A Long Sensitive Time Wilson Cloud Chamber, Donald A. Rinker

Masters Theses

"A long-sensitive time Wilson Cloud Chamber has been built and tested. A usable sensitive time of 2.5 seconds has been achieved by the use of a system of five expansion valves, the first three of which are used to obtain the sensitive time and the final two to continue the expansion at a supersaturation slightly less than critical in order to allow all droplets formed to grow in size and fall into the liquid. This system of continued expansion, coupled with delayed recompression, has been proved to reduce the background density in the chamber to an average operating value of …

An Application Of Cathodic Sputtering To The Etching Of Metallographic Specimens, Robert Ruch

Masters Theses

"The U. S. Bureau of Mines at Rolla, Missouri has for some years been conducting research on manganese-copper alloys. The study of the physical metallurgy of these alloys -- dissimilar metal couples -- has always been complicated by the difficulty of satisfactorily etching this material. It was felt that by introducing a new etching technique, cathodic bombardment, satisfactory etching might be accomplished. On this basis the following research program was proposed:

1) To survey the present state of art of cathodic etching, etching by means of cathodic sputtering;

2) To design and construct suitable equipment for the experimental study of …

An Improved Long Sensitive Time Wilson Cloud Chamber, Clarence W. Mettenburg

Masters Theses

"The discovery of numerous new particles in recent years such as mesons and hyperons causes one to speculate about the possible existence of still other particle types….

A cloud chamber seems to be a most suitable means of detecting particles ionizing less than the minimum ionization of the electron because it is capable of detecting almost all the ions produced. The cloud chamber makes it possible to study not only a wide range of ionization but also many fine details of track structure which would go unnoticed by other means of detection….

With the information and experience gained by the …

Iterative Solutions Of Kirkwood's Integral For Liquid Argon, Eugene D. Fabricius

Masters Theses

"A liquid or a dense gas may be regarded either as a very imperfect gas in which multiple collisions are frequent or as a distorted crystal in which the long range order has been lost. The crystal-like approach has not led to formal solutions, but it has led to several approximate treatments which can be used to give numerical results.

The two main types of approaches which have been used are: the cell theories, in which the liquid is regarded as a distorted crystal with one molecule located at or near each lattice point; and the hole theories, in which …

Effect Of Change In Moment Of Inertia On The Intensity Distribution In P And R Branches Of C OoV Molecules, Gordon A. Gallup

Gordon Gallup Publications

The effect of the change in moment of inertia part of the interaction between vibration and rotation on the intensities of parallel bands of linear polyatomic molecules has been determined to the first order. The results are quite similar to those of Herman and Wallis for diatomic molecules. The interaction term depends on among others a quantity, ξ _k, different in general for each band. Perpendicular bands do not show a first-order correction. A ``sum rule'' for the ξ _k has been determined.

A Study Of Current Noise In Cokes, Carbons, And Graphites, Robert J. Lanter

Physics & Astronomy ETDs

This study shows that current noise occurs when there is a deviation of Ohm's Law, i.e., when the applied voltage and resultant current are no longer proportional. Since most, and perhaps all, cases of occurrence of frequency and current dependent noise are associated with non-linear devices, e.g., semiconductors, diodes, vacuum tubes, insulators near breakdown, it seems reasonable to seek a mechanism involving non-linearity as an important feature. Even though it may not be justifiable to seek a single mechanism to explain all of the occurrences of current noise, nevertheless, the fact that in cases studied and discussed herein …

A Cloud Chamber Study Of Penetrating Showers In Aluminum, Copper And Lead, James Francis Kenney

Physics & Astronomy ETDs

In recent years, much work has been done in the investigation of high-energy nuclear collisions in various materials. The purpose of these investigations is to gain a better understanding of nucleon-meson-nucleon interactions at high energies. Laboratory accelerating devices are capable at the present time of attaining energies which are still very low in comparison to the upper limit of the cosmic radiation energy spectrum. As a result, these investigations are best carried out by using the very hard component of the cosmic radition as the primary particle of the collision.

A Chemical Ozone Measuring Radio Sonde, Alan W. Peterson

Physics & Astronomy ETDs

The Vertical distribution of atmospheric ozone has been determined spectroscopically either from surface observations or from balloon-borne spectrographs sent aloft. These spectrographic techniques have several disadvantages. Surface observations of the "Umkehr Effect" give only a rough distribution, four or five points for the entire atmosphere.

A Pulse Length Analyzer, Paul Scheie

Physics & Astronomy ETDs

For experiments involving small scintillators and for experiments involving scintillator telescopes, the circuitry may closely resemble that used with geiger counters. However, if it is desired to make use of the variation in the signal amplitude in a large scintillator, some means must be found to deal with a wide range of amplitudes. The scintillator employed in the experiment to which this work relates is a tank 10 feet in diameter that contains 300 gallons of activated toluene; light of the scintillations is collected by a 16 inch photo-multiplier tube that is located on top of the tank.

A Differential Counting Rate Meter For Low Counting Rates, James J. Schmidt

Open Access Master's Theses (through 2010)

A counting rate meter was constructed after a circuit suggested by Harald Trefall, with a power supply after Elmore.The instrument was tested and proved quite stable after operating for several weeks.The response of the instrument was calculated and the experimental results verified the calculations.Methods of calibration and operation of the instrument were developed to obtain the full benefit of its design.A set of calibration curves was obtained from the counting rate meter and a suggestion for their use in interpreting the output was made.

The research resulted in the construction of an instrument with the following specifications:

Maximum Counting Rates: …

Volume 3, Number 1 - May 1957

The Entropy

The Entropy (also published as the Providence College Journal of Physics and Chemistry) was an undergraduate scholarship journal published by the Phi Chi Club of Providence College. (Volume 3, Number 1 - May 1957 - 19 pages in total.)

Determination Of The Field Gradient Of The Marquette University Magnet, Jerome L. Zaharias

Bachelors’ Theses

The Marquette University Physics Department is interested in knowing the field gradient of the magnet being used in the research laboratory there. It is our assignment, with the apparatus at hand, to determine the field gradient of the magnet to the limit of our apparatus.

Structure Of Ch2, Gordon A. Gallup

Gordon Gallup Publications

CH₂
Recent mechanism studies have created interest in the question of the spin multiplicity in the molecular fragment CH₂. The present note concerns a detailed quantum-mechanical calculation, using the LCAO-MO approximation, undertaken to determine if numerical calculations indicate any preference of one state over the other.

Applications Of The Silicon Solar Cell In High Altitude Research, James G. Busse

Journal of the Minnesota Academy of Science

No abstract provided.

Specificity Of Intermolecular Forces Due To Quantummechanical And Thermal Charge Fluctuations*, Herbert Jehle

Department of Physics and Astronomy: Faculty Publications

The preceding note¹ (Paper I) developed the theory of the specificity of some intermolecular forces: the forces due to fluctuations of electric charge distribution in and over the interacting molecules. It was found that for a mixture of molecules in a liquid medium these forces cause a rearrangement of the molecules, so that molecules which have the same distribution of oscillator polarizabilities and oscillator orientations over the frequency spectrum tend to associate. This means that like molecules tend to become nearest neighbors. For that reason it was said that there is specific attraction between identical molecules.

Specificity Of The London-Eisenschitz Wang Force*, Jerrold M. Yos, William L. Bade, Herbert Jehle

Department of Physics and Astronomy: Faculty Publications

The London force between macromolecules immersed in a liquid medium has an interesting property which may be of biological significance. For the purpose of formulating the London interaction, one may represent each macromolecule by a set of electric dipole oscillators of specified polarizability, frequency, and orientation. To consider the simplest case, one may study macromolecules of globular form not in direct contact with each other. (They might be separated by Debyeiuckel- Onsager atmospheres made up of molecules from the medium; then the equilibrium distance between the macromolecules would be regulated by concentration changes in the ionic medium.)' Such a geometrical …

Internal Friction In Manganese Copper Alloys, William Paul Dixon

Masters Theses

"The study of the physical properties of the manganese-copper alloys is an intriguing one. These alloys show promise of usefulness in instances in which high internal friction is needed to reduce the noise and vibrational stresses at resonant frequencies of a part of a machine. The purpose of this study has been to learn more about the internal friction of manganese-copper alloys as a function of temperature, stress amplitude, frequency, time, and past history of the specimen. From this information the mechanism for absorption of vibrational energy is proposed, or at least some progress has been made toward its determination. …

Detection Of Low Energy Positive Ions By Scintillation Methods, Graydon J. Hanson

Masters Theses

"This thesis deals with the feasibility of efficiently detecting low energy positive ions, those with energies of less than several hundred electron volts, using phosphors.

The scintillation technique, first used visually and greatly improved in the last ten years by the use of a photomultiplier tube, has greatly advanced detection in high energy fields. The photomultiplier is capable of delivering milliampere pulses of current of short duration and these can be registered directly by the many electronic devices currently in use.

Extensive work has been done with phosphors which scintillate under which energy bombardment, due in part to their wide …