Halliday Exercícios Resolvidos - instructor's manual

Halliday Exercícios Resolvidos - instructor's manual

(Parte 1 de 11)

Instructor’s Manual for

Seventh Edition by David Halliday, Robert Resnick, and Jearl Walker

Prepared by

J. Richard Christman

Professor Emeritus United States Coast Guard Academy with the assistance of

Stanley A. Williams Iowa State University

Walter Eppenstein Rensselaer Polytechnic Institute

This manual contains material designed to be useful in the design of an introductory physics course based on the text FUNDAMENTALS OF PHYSICS, seventh edition, by David Halliday, Robert Resnick, and Jearl Walker. It may be used with either the extended or regular versions of the text. Section One includes material to help instructors choose topics and design courses. Section Two contains a discussion of sources for ancillary material that might be helpful in designing a course or obtaining lab and demonstration apparatus and audio/visual material. Section Three contains lecture notes outlining the important topics of each chapter, suggested demonstration and laboratory experiments, computer software, video cassettes, and DVDs.

Sections Four, Five, and Six contain answers to checkpoints, end-of-chapter questions, and endof-chapter problems. To help ease the transition from the sixth to the seventh edition of the text, Section Seven of the manual cross references end-of-chapter problems between the two editions. Because some instructors avoid assigning problems that are discussed in A Student’s Companion, in the Student Solution Manual or on the Wiley website, while others desire to include a few of these in many assignments, Section Eight of the manual contains a list of these problems.

The principal author is grateful to Stanley Williams, who co-authored the first edition of the instructor manual for Fundamentals of Physics. Much of his material has been retained in this manual. He is also grateful to Walter Eppenstein, who helped with suggestions for demonstration and laboratory experiments. Jearl Walker helped significantly by supplying answers to checkpoint questions, end-of-chapter questions, and end-of-chapter problems.

The author is indebted to the Project Editor Geraldine Osnato, who managed many aspects of this project. Special thanks go to Sharon Prendergast, the Production Editor. Karen Christman carefully read earlier editions of the manuscript and made many useful suggestions. Her fine work is gratefully noted. The unfailing support of Mary Ellen Christman is joyfully acknowledged.

J. Richard Christman Professor Emeritus U.S. Coast Guard Academy New London, Connecticut 06320

Preface i iv iv

About the Text1

Section One

Suggestions for the Course5

Section Two

Lecture Notes1

Section Three

Answers to Checkpoints164

Section Four

Answers to Questions170

Section Five

Answers to Problems179

Section Six

with the Sixth Edition233

Section Seven Comparison of Problems

and on the Wiley website265

Section Eight Problems in the Student Solution Manual, in the Student’s Companion, Table of Contents v vi vi

Fundamentals of Physics, seventh edition, follows the sequence of topics found in most introductory courses. In fact, earlier editions of this text were instrumental in establishing that sequence. It is, however, extremely flexible in regard to both the range of topics and the depth of coverage. As a result, it can be used for a two, three, or four term course along traditional lines. It can also be used with many of the innovative courses that are presently being designed and taught. In many instances sections that discuss fundamental principles and give applications are followed by other sections that go deeper into the physics. Some instructors prefer to cover fewer topics than others but treat the topics they do cover in great depth. Others prefer to cover more topics with less depth. Courses of both types can easily be accommodated by selecting appropriate sections of the text.

By carefully choosing sections of the text to be included, your course might be a two-term, in-depth study of the fundamentals of classical mechanics and electromagnetism. With the addition of another term you might include more applications and the thermodynamics and optics chapters. In a three-term course, you might also forgo thermodynamics and optics but include Chapter 37 (Relativity) and some of the quantum mechanics chapters added in the extended version.

When designing the course, some care must be taken in the selection of topics because many discussions in later chapters presume coverage of prior material. Here are some comments you might find useful in designing your course. Also refer to the Lecture Notes section of this manual.

Mechanics. The central concepts of classical mechanics are covered in Chapters 1 through 1. Some minor changes that are possible, chiefly in the nature of postponements, are mentioned in the Lecture Notes. For example, the scalar product can be postponed until the discussion of work in Chapter 7 and the vector product can be postponed until the discussion of torque in Chapter 1.

Coverage of Chapter 5 can be shortened to two lectures or elongated to over four, depending on the time spent on applications. Sections 9—8, 9—9, 9—10, and 9—1, on collisions, can be covered as part of laboratory exercises. Other sections in the first twelve chapters that can be used to adjust the length of the course are 2—10, 3—7, 4—8, 4—9, 6—4, 7—8, 9—10, 9—1, 9—12, 1—5, and 1—12. Section 10—7, which deals with the calculation of the rotational inertias of extended bodies, can be covered in detail or can be shortened by simply stating results once the definition as a sum over particles has been discussed. The parallel axis theorem is needed to solve some end-of-chapter problems in this chapter and in Chapter 16 and it should be covered if those problems are assigned.

The order of the chapters should be retained. For example, difficulties arise if you precede dynamics with statics as is sometimes done in other texts. To do so, you would need to discuss torque, introduced in Chapter 10, and explain its relation to angular acceleration. This involves considerable effort and is of questionable value.

Chapters 12 through 18 apply the fundamental principles of the first 1 chapters to special systems and, in many cases, lay the groundwork for what is to come. Many courses omit one or more of Chapters 12 (Equilibrium and Elasticity), 13 (Gravitation), 14 (Fluids), and 17 (Waves – I). There is some peril in these omissions, however. Chapter 13, for example, is pedagogically important. The central idea of the chapter is a force law and the discussions of many of its ramifications show by example how physics works. Since the chapter brings together many previously discussed ideas it can be used as a review. In addition, Newton’s law of gravity is used later to introduce Coulomb’s law and the proof that the electrostatic force is conservative relies on the analogy. The basis of Gauss’ law is laid in Chapter 13 and inclusion of this chapter makes teaching

About the Text 1 of the law easier.

The idea of a velocity field is first discussed in Chapter 14 and is used to introduce electric flux in Chapter 23 (Gauss’ Law). The concepts of pressure and density are explained in Chapter 14 and are used again in the thermodynamics chapters. If Chapter 14 is omitted, you should be prepared to make up for the loss of material by presenting definitions and discussions of velocity fields, pressure, and density when they are first used in your course.

Chapter 12 (Equilibrium and Elasticity) can be safely omitted. If it is, a brief description of the equilibrium conditions might be included in the discussion of Chapter 10 or 1. The few problems in later chapters that depend on material in this chapter can be passed over. If Chapter 12 is included, be sure you have already covered torque and have explained its relation to angular acceleration.

Chapters 15 (Oscillations) and 16 (Waves – I) are important parts of an introductory course and should be covered except when time constraints are severe. Chapter 15 is required for Chapter 16 and both are required for Chapter 17 (Waves – I). Chapter 15 is also required for Chapter 31 (Electromagnetic Oscillations and Alternating Current) and parts of Chapter 16 are required for Chapters 3 (Electromagnetic Waves), 35 (Interference), 36 (Diffraction), 38 (Photons and Matter Waves), and 39 (More About Matter Waves). Chapters 15 and 16 may be covered in the mechanics part of the course or may be delayed until electromagnetic waves are covered.

Thermodynamics. Chapters 18 through 20 cover the ideas of thermodynamics. Most two-term courses and some three-term courses omit these chapters entirely. If they are covered, they can be placed as a unit almost anywhere after the mechanics chapters. The idea of temperature is used in Chapter 26 (Current and Resistance) and in some of the modern physics chapters, as well as in the other thermodynamics chapters. If Chapter 18 is not covered prior to Chapter 26, you should plan to discuss the idea of temperature in connection with that chapter or else omit the section that deals with the temperature dependence of the resistivity. Sections of these chapters that can be used to adjust the length of the course are 18—6, 18—12, 19—6, 19—10, 20—5, 20—6, 20—7, and 20—8.

Electromagnetism. The fundamentals of electricity and magnetism are covered in Chapters 21 through 3. Chapter 3 (Electromagnetic Waves) may be considered a capstone to the electromagnetism chapters or as an introduction to the optics chapters. Sections that might be omitted to adjust the length of the course are 21—5, 24—8, 25—6, 25—7, 25—8, 26—6, 26—8, 26—9, 27—8, 27—9, 28—7, 30—9, 30—12, 31—1, 32—6, 32—7, 32—8, 32—9, 32—10, 32—1, and 3—7. Sections 3-8, 3—9, and 3—10 can be om8itted if the optics chapters are not covered. Otherwise, they must be included.

Sections 25—6, 25—7, and 25—8, on dielectrics, should be included in an in-depth course but may be omitted in other courses to make room for other topics. Similarly, coverage of Chapters 27 (Circuits) and 31 (Electromagnetic Oscillations and Alternating Currents) may be adjusted considerably, depending on the extent to which the course emphasizes practical applications. They may also be covered as laboratory exercises. Section 26—6 is required if Chapter 41 is covered although the material can be shorted and presented in conjunction with Chapter 41 rather than at an earlier time.

Section 32—2 contains a discussion of Gauss’ law for magnetism, one of Maxwell’s equations, and should be included in every course, as should sections 32—3, 32—4, and 32—5, on the displacement current, the Ampere-Maxwell law, and the complete set of Maxwell’s equations. The last portion of the chapter deals with magnetic properties of materials and some of ramifications of those properties. It nicely complements the previous sections on dielectrics. These parts of the chapter might be omitted or passed over swiftly to gain time for other sections. On the other hand, they should be included if you intend to emphasize properties of materials.

Optics. Chapters 34 through 36 are the optics chapters. You might wish to precede them

2 About the Text with Chapter 3 (Electromagnetic Waves) or you might wish to replace Chapter 3 with a short qualitative discussion. You can be somewhat selective in your coverage of Chapter 34 (Images). It can be covered as lightly or as deeply as desired. Much of the material in this chapter can be covered as laboratory exercises.

Chapters 35 (Interference) and 36 (Diffraction) are important in their own right and are quite useful for the discussion of photons and matter waves in Chapter 38. Chapter 36 cannot be included without Chapter 35 but coverage of both chapters can be reduced somewhat to make room for other topics. The fundamentals of interference and diffraction are contained in Sections 35—1 through 35—6 and 36—1 through 36—5. Other sections of these chapters can be included or excluded, as desired.

Modern Physics. Chapter 37 (Relativity) may be used as a capstone to the mechanics section of the course, as a capstone to the entire course, or as an introduction to the modern physics included in the extended version of the text. Some results of relativity theory are needed for the chapters that follow. If you do not wish to cover Chapter 37 in detail you can describe these results as they are needed. However, it is probably more satisfying to present a more complete and logically connected description of relativity theory. If you plan to cover some of the other modern physics chapters you should consider including Chapter 37.

The fundamentals of the quantum theory are presented in Chapters 38 (Photons and Matter

Waves) and 39 (More About Matter Waves). This material should be treated as a unit and must follow in the order written. If you include these chapters, be sure earlier parts of the course include discussions of uniform circular motion, angular momentum, Coulomb’s law, electrostatic potential energy, electromagnetic waves, and diffraction. E = mc2 and E2 =( pc)2 +( mc2)2, from relativity theory, are used in discussions of the Compton effect.

The introductory modern physics chapters are followed by application chapters: Chapters 40

(All About Atoms), 41 (Conduction of Electricity in Solids), 42 (Nuclear Physics), 43 (Energy from the Nucleus), and 4 (Quarks, Leptons, and the Big Bang). You may choose to end the course with Chapter 39 or you may choose to include one or more of the application chapters.

The ideas of temperature and the Kelvin scale are used in several places in the modern physics chapters: Sections 40—12 (How a Laser Works), 41—5 (Metals), 41—6 (Semiconductors), 43—6 (Thermonuclear Fusion: The Basic Process), and 4—12 (The Microwave Background Radiation). With a little supplementary material, these sections can be covered even if Chapter 18 is not.

Chapter 43 (Energy from the Nucleus) requires Chapter 42 (Nuclear Physics) for background material, but Chapter 42 need not be followed by Chapter 43. E = mc2 and E2 =( pc)2 +( mc2)2 from relativity theory are also used. The discussion of thermonuclear fusion uses some of the ideas of kinetic theory, chiefly the distribution of molecular speeds. Either Chapter 19 (particularly Section 19—7) should be covered first or you should be prepared to supply a little supplementary material here.

Chapter 4 includes an introduction to high energy particle physics and tells how the ideas of physics are applied to cosmology. Both these topics fascinate many students. In addition, the chapter provides a nice overview of physics.

Some knowledge of the Pauli exclusion principle (from Chapter 40) and spin angular momentum (from Chapters 32 and 40) is required. Knowledge of the strong nuclear force (discussed in Chapters 42 and 43) is also required. In addition, beta decay (discussed in Chapter 42) is used several times as an illustrative example. Nevertheless, the chapter can be made to stand alone with the addition of only a small amount of supplementary material.

A bare bones two-semester course (about 90 meetings) can be constructed around Chapters 1 through 1, 15, 16, and 21 through 3, with the omission of Chapter 31 Sections 32—7 through 32—

About the Text 3

(Parte 1 de 11)