Digital Commons Network^™

Physics, Chapter 3: The Equilibrium Of A Particle, Henry Semat, Robert Katz

Robert Katz Publications

A particle which remains at rest or in uniform motion with respect to its frame of reference is said to be in equilibrium in that frame. Centuries ago it was recognized that the state of rest was a natural state of things, for it was observed that objects set in motion on the surface of the earth tended to come to rest. The maintenance of any horizontal motion on earth was thought to require the continued exercise of a force, hence to be a violent motion, while vertical motion like that of a falling body was thought to be natural …

Physics, Chapter 2: Motion Of A Particle (Kinematics), Henry Semat, Robert Katz

Robert Katz Publications

Normally, when we say an object is at rest, we mean that it is at rest with respect to the surface of the earth; when we say a car is moving at a speed of 40 mi/hr, we imply that the motion is taking place at this speed relative to the road. A boat sailing on the river moves with respect to the river's banks, but it also moves with respect to the flowing water in the river. The lift on the wings of an airplane is generated by the motion of the airplane through the air, but it is …

Physics, Chapter 21: Vibrations And Sound, Henry Semat, Robert Katz

Robert Katz Publications

There are two aspects of sound: one is the physical aspect which involves the physics of the production, propagation, reception, and detection of sound; the other, which is the sensation of sound as perceived by the individual, depends upon physiological and psychological effects. It is not desirable to separate the two aspects of sound completely, but the main emphasis in this book must necessarily be on the physical aspect. In this chapter we shall consider mostly musical sounds. A vocabulary has been developed to describe the sensation experienced when a musical sound is heard. Such terms as the pitch of …

Physics, Chapter 37: Reflection And Refraction, Henry Semat, Robert Katz

Robert Katz Publications

In the passage of a beam of light through a medium, some of the radiant energy is absorbed and is transformed into internal energy, while some of it is scattered in all directions. The oscillating electric field associated with the light wave sets some of the electrons of the medium into oscillation, thus giving up some of its energy, and these oscillating electrons subsequently reradiate energy as scattered electromagnetic radiation. Scattering therefore takes place only in the presence of matter. The color of the sky is due to the small amount of scattering of sunlight by the molecules of the …

Physics, Chapter 32: Electromagnetic Induction, Henry Semat, Robert Katz

Robert Katz Publications

When a wire moves through a uniform magnetic field of induction B, in a direction at right angles to the field and to the wire itself, the electric charges within the conductor experience forces due to their motion through this magnetic field. The positive charges are held in place in the conductor by the action of interatomic forces, but the free electrons, usually one or two per atom, are caused to drift to one side of the conductor, thus setting up an electric field E within the conductor which opposes the further drift of electrons. The magnitude of this …

Physics, Chapter 31: Forces On Moving Charges And Currents, Henry Semat, Robert Katz

Robert Katz Publications

Ampere was the first to show that wires carrying current experienced forces when placed in magnetic fields. Later it was shown that charged particles moving in magnetic fields also experience forces. Common applications of these phenomena are the electric motor, the galvanometer, and the cathoderay tube. Since a moving electric charge is equivalent to a current, we shall first consider the force acting on a charge q moving with velocity v in a magnetic field of induction B. Experiment shows that the force F acting on the charge q is at right angles to the directions of both v and …

Physics, Chapter 7: Work And Energy, Henry Semat, Robert Katz

Robert Katz Publications

An extremely important concept that has been developed in physics is that of the work done on a body by the action of some external agent which exerts a force on this body and produces motion. For example, whenever someone lifts a body, he does work by exerting a force upward on it and moving it upward. Whenever a steam locomotive pulls a train, a series of processes takes place in the steam engine of the locomotive which enables it to exert a force on the train and move it in the direction of the force. The term work, as …

Physics, Chapter 39: Optical Instruments, Henry Semat, Robert Katz

Robert Katz Publications

The photographic camera uses a converging lens to form a real, inverted image of an object. The image is focused on a film or plate which is coated with an emulsion containing silver bromide crystals. When a few incident quanta of light are absorbed in a grain of emulsion, the grain becomes activated and developable, and when the plate is developed, the bromine is removed from each activated grain, leaving a clump of silver behind. When the plate is "fixed," the remaining emulsion is removed from the plate, so that the image is made permanent. In most cameras the converging …

Physics, Chapter 45: Natural Radioactivity, Henry Semat, Robert Katz

Robert Katz Publications

The discovery of an important phenomenon usually leads to other important discoveries. The discovery of x-rays by Roentgen in 1895 led to the discovery of radioactivity by Becquerel in 1896. In the gas type of x-ray tube used by Roentgen, the glass walls of the tube were observed to fluoresce. Becquerel was interested in determining whether there was any relationship between the fluorescence of the glass of an x-ray tube and the phosphorescence of certain salts which were irradiated by ordinary light. One of the salts used by Becquerel was the double sulphate of uranium and potassium. He wrapped a …

5. Newton, Robert L. Bloom, Basil L. Crapster, Harold A. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section VIII: The Development of Modern Science

Isaac Newton (1642-1727) was born and educated in England. He attended Trinity College, Cambridge, and there found the inspiration for his prodigious work that was to synthesize and extend the labors of Copernicus, Galileo, Kepler, and others beyond the wildest dreams of any of them. Newton was the intellectual giant who set the direction of the physical sciences on the paths they were to follow undeviatingly into the twentieth century. [excerpt]

Xx. Meaning In The Physical Sciences, Robert L. Bloom, Basil L. Crapster, Harold L. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section XX: Meaning in the Physical Sciences

The twentieth century has seen two major revolutions in our theories of physics concerning nature, and these have made us change many of our concepts about the terms in which nature can be described. The new theories born in these revolutions are the theory of relativity and of quantum mechanics. The biological sciences had their revolutions in the nineteenth century, and while remarkable progress has been made since, nothing comparable to that upheaval has occurred in this century. Of the two massive changes in the concepts of the physical sciences, we can discuss but one here. [excerpt]

1. The Problem, Robert L. Bloom, Basil L. Crapster, Harold L. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section XX: Meaning in the Physical Sciences

Newton's laws of motion and their associated definitions encountered their first difficulty near the middle of the nineteenth century.

Newton had designed his theory to describe the behavior of matter in space and time by inventing a relationship between the force on a body and the resulting change in motion of the body. Such a description of nature came to be called mechanical, and a large part of physicists' efforts were directed toward reducing all aspects of physics to mechanics. These efforts were rewarded magnificently in the fields of heat, electricity, and sound, in addition to astronomy and other more …

Simple Themistor Bridge For Absorbed Radiation Measurement, Jack G. Dodd

Journal of the Arkansas Academy of Science

No abstract provided.

Investigation Of The Geometric Effects Connected With The U-Effect-Iii, Anthony Edward Hoffman

Masters Theses

"Statement of Problem: The investigation reported herein is of the dependence of the voltage output due to the U-Effect-III upon the geometry of the tube. The geometry of the tube is defined to include the inner diameter of the tube as well as the size and number of the mercury and electrolyte drops. The previous experimental study of the effect did not include an investigation of the effects of the geometry of the tube, as defined above, on the voltage output. It seems that information as to the dependence of the output voltage on the geometry of the tube would …

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 …

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 …

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 …

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 …

Semi-Conducting Properties Of Gray Tin As A Laboratory Introduction To Solid State Physics, Glenn F. Powers, Gene E. Louallen, Robert M. Rickett

Journal of the Arkansas Academy of Science

No abstract provided.

Physics, Preface, Henry Semat, Robert Katz

Robert Katz Publications

This book is intended for students of science and engineering; it aims to develop both an understanding of the important concepts of physics and some analytical skill in the solutions of problems. The mathematical level of the book is such that it may be used by students who are taking a course in calculus concurrently.

The notations and methods of the calculus are introduced early in the text, beginning with the concept of a derivative in the discussion of motion, and are then extended to more complex problems as the student progresses both in physics and in mathematics. Vector algebra …

Physics, Chapter 11: Rotational Motion (The Dynamics Of A Rigid Body), Henry Semat, Robert Katz

Robert Katz Publications

The motion of the flywheel of an engine and of a pulley on its axle are examples of an important type of motion of a rigid body, that of the motion of rotation about a fixed axis. Consider the motion of a uniform disk rotating about a fixed axis passing through its center of gravity C perpendicular to the face of the disk, as shown in Figure 11-1. The motion of this disk may be described in terms of the motions of each of its individual particles, but a better way to describe the motion is in terms of …

Physics, Chapter 20: Wave Motion, Henry Semat, Robert Katz

Robert Katz Publications

Wave motion is an important method of transferring energy from one place to another without involving the actual transfer of matter. When a pebble is dropped into a still pool, some of the kinetic energy of the pebble is used to generate the ripples which spread out in all directions over the surface of the pool. When the ripples pass by a floating object, such as a bit of cork, the cork bobs up and down, having acquired its kinetic energy of vibration from the ripple system. The ripples thus serve to deliver some of the energy of the pebble …

Physics, Chapter 19: Heat Engines, Henry Semat, Robert Katz

Robert Katz Publications

In this chapter we shall consider the physical principles underlying the operations of heat engines because of the intrinsic importance of these principles and because of the part they have played in the development of fundamental physical ideas. Heat engines are designed and built to convert heat into work. In most cases the heat is obtained from the combustion of a common fuel such as coal, oil, gasoline, or natural gas. An important new source of heat that is just beginning to be used, and will be used more extensively in the future, is the mass which is converted into …

Physics, Appendix A, Henry Semat, Robert Katz

Robert Katz Publications

Appendix A

Physics, Chapter 46: Nuclear Reactions, Henry Semat, Robert Katz

Robert Katz Publications

One of the most important developments of twentieth-century physics was the formulation of the special theory of relativity. This theory was an outgrowth of the failure of all attempts to show that the motion of the source of light relative to the observer had any effect on the speed of light. It is impossible to account for these experimental findings of Michelson and Morley, and others, on the basis of classical mechanics and electromagnetic theory. In 1905, Albert Einstein put forth the suggestion that all experimental findings would be clarified if it were assumed that the speed of light is …

Physics, Chapter 42: Optical Spectra And Atomic Structure, Henry Semat, Robert Katz

Robert Katz Publications

When light passes through a prism spectroscope or a diffraction-grating spectroscope, an optical spectrum is obtained in which the intensity of the radiation may be analyzed as a function of wavelength. The spectrum may be observed visually in the limited wavelength region to which the eye is sensitive; it may be focused on a photographic plate or upon a thermocouple or thermopile. Our knowledge of the structure of atoms and molecules is largely dependent upon the analyses of optical spectra, for these spectra are characteristic of the emitting atoms or molecules. Even before the spectra of atoms were properly understood …

Physics [Complete Work], Henry Semat, Robert Katz

Robert Katz Publications

This book is intended for students of science and engineering; it aims to develop both an understanding of the important concepts of physics and some analytical skill in the solutions of problems. The mathematical level of the book is such that it may be used by students who are taking a course in calculus concurrently.

The notations and methods of the calculus are introduced early in the text, beginning with the concept of a derivative in the discussion of motion, and are then extended to more complex problems as the student progresses both in physics and in mathematics. Vector algebra …

Liesegang Rings, Robert Edward Young

Masters Theses

"Although the discovery of the "Liesegang Rings" phenomenon was made sometime before 1855 little was done in the way of study or experimentation until 1896 when R. E. Liesegang discovered that if a crystal or strong solution of silver nitrate is added to a gelatin gel containing dilute potassium chromate, the resulting precipitate of silver chromate is not continuous, as might be expected, but forms a discontinuous periodic pattern. This pattern follows a geometric progression law, x_n = akⁿ, where x_n is the position of the n^th ring, and a and k are constants. K …

Physics, Contents, Henry Semat, Robert Katz

Robert Katz Publications

Table of contents

Physics, Chapter 1: Fundamental Quantities, Henry Semat, Robert Katz

Robert Katz Publications

Physics is a fundamental science dealing with matter and energy. By convention, the subject matter of physics has been divided into such topics as mechanics, heat, sound, light, and electricity. In addition to these general classifications, present-day physics includes atomic physics, nuclear physics, solid-state physics, chemical physics, biophysics, and many other subdivisions. It is impossible to include all aspects of physics in a single definition or paragraph, and to distinguish physics clearly from its nearest neighbors, the other physical sciences-astronomy., chemistry, and geology.