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Full-Text Articles in Physics
Physics [Complete Work], Henry Semat, Robert Katz
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 …
Physics, Preface, Henry Semat, Robert Katz
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 12: Periodic Motion, Henry Semat, Robert Katz
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
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 9: Hydrodynamics (Fluids In Motion), Henry Semat, Robert Katz
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 4: Statics Of A Rigid Body, Henry Semat, Robert Katz
Physics, Chapter 4: Statics Of A Rigid Body, Henry Semat, Robert Katz
Robert Katz Publications
In the preceding chapter we observed that a particle would remain in equilibrium, in a state of rest, or in a state of uniform motion in a straight line when the resultant of all the forces acting on it was equal to zero. This condition for equilibrium was extended to larger bodies under either of two possible conditions: If the forces acting on the body were concurrent, that is, if they were directed toward a single point, the body could be treated as if it were a particle; or if the body moved with uniform translational motion in which every …
Physics, Chapter 3: The Equilibrium Of A Particle, Henry Semat, Robert Katz
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
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 28: Electrical Conduction In Liquids And Solids, Henry Semat, Robert Katz
Physics, Chapter 28: Electrical Conduction In Liquids And Solids, Henry Semat, Robert Katz
Robert Katz Publications
We have seen that electrical conduction in solids is associated with the drift of free electrons in the solid, a process which will be examined in greater detail in Section 28-4. A similar mechanism may be used to account for the conduction of electricity in liquid metals. In other liquids electricity is conducted by the migration of positive and negative ions through the liquid.
Physics, Chapter 27: Direct-Current Circuits, Henry Semat, Robert Katz
Physics, Chapter 27: Direct-Current Circuits, Henry Semat, Robert Katz
Robert Katz Publications
When a charged particle traverses a closed path in an electrostatic field in space, the total work done on the particle is zero. The electric field is conservative. Associated with each point in the field, there is a fixed value of the electrical potential.
In a simple circuit consisting of a chemical cell and a resistor, as shown in Figure 27-1, we have seen that the current flows through the resistor from the positive terminal of the cell to the negative terminal of the cell. The positive terminal is at the higher potential, so that the current flows from the …
Physics, Chapter 25: Capacitance And Dielectrics, Henry Semat, Robert Katz
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 23: The Electric Field, Henry Semat, Robert Katz
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 21: Vibrations And Sound, Henry Semat, Robert Katz
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 16: Kinetic Theory Of Gases, Henry Semat, Robert Katz
Physics, Chapter 16: Kinetic Theory Of Gases, Henry Semat, Robert Katz
Robert Katz Publications
The behavior of a gas under various conditions of temperature and pressure has already been studied in some detail. When the pressure of a constant mass of gas is not too great, say less than about 2 atm, we find that a gas obeys the following relationships to be discussed.
Physics, Chapter 15: Heat And Work, Henry Semat, Robert Katz
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
Physics, Appendix C, Henry Semat, Robert Katz
Robert Katz Publications
Appendix C: Answers to Odd-Numbered Problems
Physics, Appendix A, Henry Semat, Robert Katz
Physics, Chapter 45: Natural Radioactivity, Henry Semat, Robert Katz
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 …
Physics, Chapter 40: Light As A Wave Motion, Henry Semat, Robert Katz
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 39: Optical Instruments, Henry Semat, Robert Katz
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 36: Light And Its Measurement, Henry Semat, Robert Katz
Physics, Chapter 36: Light And Its Measurement, Henry Semat, Robert Katz
Robert Katz Publications
The word light, as commonly used, refers to the radiant energy which produces a visual effect. It was first shown by Maxwell that light is an electromagnetic radiation, propagated with a speed whose value was numerically determined by the relationship between electric and magnetic units.
Physics, Chapter 35: Electronics, Henry Semat, Robert Katz
Physics, Chapter 35: Electronics, Henry Semat, Robert Katz
Robert Katz Publications
The electrons of an atom occupy certain energy levels when the atom is far from other atoms. When a large number of atoms are assembled to form a conducting metallic solid, the energy levels of the valence electrons are displaced in position to form a conduction band, as discussed in Section 28-4. The valence electrons occupy energy levels within the conduction band and are relatively free to drift from atom to atom within the metal. In accordance with a fundamental physical principle, known as the Pauli exclusion principle, only 1 electron may occupy a particular energy level. The conduction electrons …
Physics, Chapter 31: Forces On Moving Charges And Currents, Henry Semat, Robert Katz
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 …