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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 …

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]

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, 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 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 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, 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 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, 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 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, 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 …

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 …

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 …

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 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: …

A Probe For Measuring Ultrasonic Pressures, Robert F. Rohrer

Masters Theses

"In the study of acoustics, the term ultrasonics is defined as those wave motions that have frequencies greater than about 20,000 cycles per second. The characteristics of a sound wave at any point in a medium can be regarded as completely defined when the amplitude, frequency, and phase of its Fourier components are known.

Sound measurements at their best are difficult. In the last few years sensitive linear microphones and electronic amplifiers have become available. Still, there are two difficulties of prime importance with their use in a sound field. First, there is the precise, absolute calibration of the equipment …

Thermal Conductivity Of Sodium Chloride Within The Temperature Range 375°K To 637°K, Paul E. Ohlsen

Masters Theses

"The transport of heat in dielectric solids is attributed entirely to lattice waves whereas in metals there is in addition a transfer by the flow of valence electrons. The thermal conductivity of a non-electrical-conductor is limited by a number of scattering processes giving rise to thermal resistances. Scattering results from impurity atoms and from vacancies and dislocations within the crystal structure and from the interaction of the lattice vibrations amongst themselves. Scattering also occurs at the boundaries of the crystal. The thermal resistance of an ideal crystal at low temperatures is due almost entirely to boundary scattering and at high …

The Thermal Conductivity Of Potassium Chloride At Elevated Temperatures, Wendell D. Miller

Masters Theses

"The transport of heat in solids is attributed to the combined effect of the quantized vibrations of lattice points, or phonons, and the flow of valence electrons. In dielectric solids, the thermal conductivity is due almost entirely to phonons, while in metals the latter method preponderates. Scattering processes in dielectric solids, giving rise to thermal resistance, also serve to limit the thermal conductivity. Scattering results from vacancies, dislocations, interstitial atoms and phonon interaction. Crystal boundaries also function as scattering points and in crystals of small dimensions, this process is the most pronounced conductivity-limiting factor. At low temperatures the thermal resistance …

Some Uses Of An Oscilloscope In High School Physics, John Ray Bolte

Dissertations and Theses @ UNI

Use of the cathode ray oscilloscope in the high school physics class has, in many instances, been overlooked by the high school physics teacher as a means of increasing the student's understanding of certain electrical phenomena. In many cases, the teacher may not be well acquainted with the use of an oscilloscope and, very often, the teacher may feel that the cost of such an instrument is beyond the limits of the typical high school science budget.

The Thermal Conductivity Of Sodium Chloride At Elevated Temperatures, Howard Martin Brown

Masters Theses

"The thermal conductivity of solids has been attributed to a combined effect of the quantized vibration of the lattice points, called phonons, and the flow of valence electrons. In nonconductors the thermal conductivity is due almost entirely to phonons, as was shown by Debye, whereas in metals the conductivity is due mostly to the flow of valence electrons. After Debye, Peierls calculated the lattice conductivity at elevated temperatures using quantum mechanics and demonstrated that it is proportional to 1/T. There are not enough data available to substantiate any theory but what data there are seem to indicate a mixed conductivity …

Analysis Of Zodiacal Light Recordings, Mclane Downing

Physics & Astronomy ETDs

The object of the zodiacal light work at Capillo Peak is to take comparable records of zodiacal light intensities over an extended period of time. In order to obtain extra-terrestrial isophotes from the original recordings, corrections for loss of light intensity in the atmosphere must be made.