Digital Commons Network^™

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 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, Chapter 30: Magnetic Fields Of Currents, Henry Semat, Robert Katz

Robert Katz Publications

The first evidence for the existence of a magnetic field around an electric current was observed in 1820 by Hans Christian Oersted (1777-1851). He found that a wire carrying current caused a freely pivoted compass needle in its vicinity to be deflected. If the current in a long straight wire is directed from C to D, as shown in Figure 30-1, a compass needle below it, whose initial orientation is shown in dotted lines, will have its north pole deflected to the left and its south pole deflected to the right. If the current in the wire is reversed and …

Physics, Chapter 29: The Magnetic Field, Henry Semat, Robert Katz

Robert Katz Publications

Natural magnets, called lodestones, have been known since ancient times. The lodestone, a magnetic oxide of iron called magnetite (Fe₃O₄), was mentioned by Thales of Miletus. By the eleventh century the magnetic compass was known to the Chinese, and in the twelfth century references to the compass were made in Western Europe. The lodestone is capable of attracting pieces of iron and of imparting permanent magnetism to other pieces of iron so that these too could attract iron filings. If an iron bar is magnetized, as the result of being near a piece of lodestone, and …

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, 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 …

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.