Digital Commons Network^™

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 25: Capacitance And Dielectrics, Henry Semat, Robert Katz

Robert Katz Publications

When an isolated charged conducting sphere bears a charge Q, the potential of the sphere may be computed from the results of Section 23-6 by considering that the electric intensity outside the sphere is as though the entire charge of the sphere were concentrated at its center.

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.

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 …

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.

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 …

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 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.

Physics, Chapter 14: Temperature, Henry Semat, Robert Katz

Robert Katz Publications

Temperature is one of the fundamental concepts of physics. We are all able to recognize that some bodies are hotter than others, but our temperature sense is qualitative rather than quantitative and is capable of only a limited range. The sense of touch can frequently be used to distinguish between hotter and colder objects, provided that these lie in a temperature range consistent with the stability of human tissue. Even within this range the sense of touch is often unreliable as a measure of temperature.

The metal bracket holding a wooden rail may feel much colder to the touch than …

Physics, Chapter 12: Periodic Motion, Henry Semat, Robert Katz

Robert Katz Publications

One of the more important problems in mechanics is the study of periodic motions, that is, motions which repeat themselves in regular intervals of time, called the period. An example of periodic motion which we hrNe already encountered is uniform circular motion, in which the velocity and acceleration of the body at a given angular position were always the same. If a particle was found at a given position at a time t, we could be sure that it would return to that position at time t + T later, where T was the period of the rotational motion. A …

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 10: Momentum And Impulse, Henry Semat, Robert Katz

Robert Katz Publications

An extremely important concept in the development of mechanics is that of momentum. The momentum of a body is defined as the product of its mass by its velocity. We shall use the symbol p to denote the momentum of a body. The momentum of a body is a vector quantity, for it is the product of mass, a scalar, by velocity, a vector. While momentum and kinetic energy are compounded of the same two ingredients, mass and velocity, they are quite different concepts, and one aspect of their difference may be seen in the fact that momentum is …

Physics, Chapter 9: Hydrodynamics (Fluids In Motion), Henry Semat, Robert Katz

Robert Katz Publications

When a liquid flows through a pipe in such a way that it completely fills the pipe, and as much liquid enters one end of the pipe as leaves the other end of the pipe in the same time, then the liquid is said to flow at a steady rate. At any point of the pipe, the flow of the liquid does not change with time. The path of any particle of liquid as it moves through the pipe is called a streamline. We can map the flow of liquid through the pipe by drawing a series of …

Physics, Chapter 8: Hydrostatics (Fluids At Rest), Henry Semat, Robert Katz

Robert Katz Publications

From our everyday experience, we have become familiar with the fact that matter occurs in three different forms-solid, liquid, and gas. Under ordinary conditions stone, iron, copper, and chalk, for example, are solids; water, oil, and mercury are liquids; air, hydrogen, and carbon dioxide are gases. Each one of these forms is called a phase. At times it is difficult to distinguish clearly between the solid and the liquid phases, as in a material such as tar which flows under the action of a force at ordinary temperatures. Metals at high temperatures flow or "creep" under the action of a …

Physics, Chapter 6: Circular Motion And Gravitation, Henry Semat, Robert Katz

Robert Katz Publications

Our earlier discussion of the kinematics of a particle was developed principally from the point of view of being able to describe that motion easily within a rectangular coordinate system. Thus the most complex case with which we dealt was that of a projectile motion, in which the acceleration was constant and was directed along one of the coordinate axes. A more convenient framework within which to discuss rotational and circular motions is provided by a set of polar coordinates. In the present discussion we will restrict ourselves to motion in which the polar coordinate r is constant, or fixed; …

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 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 …