Brief Contents VOLUME Chapter Measurements in Physics Chapter Motion in One Dimension 18 Chapter Motion in Two Dimensions 41 Chapter Force and Newton s Laws of Motion 65 Chapter Work and Energy 94 Chapter Momentum and Collisions Chapter Oscillations 122 147 Chapter Rotational Motion 169 Chapter Gravitation 199 Chapter 10 Solids and Fluids 221 Chapter 11 Waves and Sound 242 Chapter 12 Temperature, Thermal Expansion, and Ideal Gases 263 Chapter 13 Heat 283 Chapter 14 The Laws of Thermodynamics 304 VOLUME Chapter 15 Electric Charges, Forces, and Fields 329 Chapter 16 Electric Energy, Potential, and Capacitors 355 Chapter 17 Electric Current, Resistance, and Circuits 377 Chapter 18 Magnetic Fields and Forces 403 Chapter 19 Electromagnetic Induction and Alternating Current 427 Chapter 20 Electromagnetic Waves and Special Relativity 453 Chapter 21 Geometrical Optics 480 Chapter 22 Wave Optics 510 Chapter 23 Modern Physics 531 Chapter 24 Atomic Physics 554 Chapter 25 Nuclear Physics 582 Chapter 26 A Universe of Particles 611 i Problem-Solving Strategies and Tactics Volume (pp 328) contains Chapters 14 Volume (pp 329 634) contains Chapters 15 26 Chapter 13 15 16 17 Chapter 11 14 18 19 21 Problem-Solving Strategy 2.1 Solving Kinematics Problems with Constant Acceleration 3.1 Solving Projectile Motion Problems 4.1 Solving Dynamics Problems 5.1 The Work-Energy Theorem 5.2 Conservation of Mechanical Energy 6.1 Conservation of Momentum 8.1 Kinematics Problems with Constant Angular Acceleration 8.2 Mechanical Equilibrium 13.1 Heating, Melting, and Vaporizing 15.1 Finding the Net Force Due to Multiple Electric Charges 16.1 Networks of Capacitors 17.1 Networks of Resistors Page 32 54 75 104 109 127 174 186 293 336 367 388 Tactic 1.1 Unit Conversions 3.1 Vector Addition and Subtraction 4.1 Drawing Force Diagrams 11.1 Intensity Level and Decibels 14.1 The First Law of Thermodynamics 18.1 Drawing Vectors in Three Dimensions 19.1 Applying Lenz s Law 21.1 Image Formation by Concave Mirrors 21.2 Image Formation by Convex Lenses Page 46 67 251 312 406 429 484 492 ii Essential COLLEGE PHYSICS FIRST EDITION Volume Chapters 14 Andrew F Rex Richard Wolfson University of Puget Sound Middlebury College Addison-Wesley Publisher: Jim Smith Executive Editor: Nancy Whilton Development Director: Michael Gillespie Development Editor: Gabriele Rennie Senior Development Editor: Margot Otway Editorial Manager: Laura Kenney Senior Project Editor: Martha Steele Editorial Assistant: Dyan Menezes Editorial Assistant: Claudia Trotch Media Producer: David Huth Director of Marketing: Christy Lawrence Executive Marketing Manager: Scott Dustan Executive Market Development Manager: Scott Frost Market Development Coordinator: Jessica Lyons Managing Editor: Corinne Benson Senior Production Supervisors: Nancy Tabor and Shannon Tozier Production Service: Pre-Press PMG Illustrations: Rolin Graphics Text Design: Elm Street Publishing Services Cover Design: Derek Bacchus Manufacturing Manager: Jeff Sargent Director, Image Resource Center: Melinda Patelli Manager, Rights and Permissions: Zina Arabia Image Permission Coordinator: Elaine Soares Photo Research: Kristin Piljay Text and Cover Printer and Binder: Courier, Kendallville Cover Image: Mark Madeo Photography Formation , four men jumping over a wall at the beach in San Francisco Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on p C-1 Copyright © 2010 Pearson Education, Inc., publishing as Pearson Addison-Wesley All rights reserved Manufactured in the United States of America This publication is protected by Copyright and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, 1900 E Lake Ave., Glenview, IL 60025 For information regarding permissions, call (847) 486-2635 Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps MasteringPhysicsTM is a trademark, in the U.S and/or other countries, of Pearson Education, Inc or its affiliates Library of Congress Cataloging-in-Publication Data Rex, Andrew F., 1956Essential college physics / Andrew F Rex, Richard Wolfson 1st ed p cm Includes index ISBN-13: 978-0-321-61116-1 (v 1) ISBN-10: 0-321-61116-0 (v 1) ISBN-13: 978-0-321-61117-8 (v 2) ISBN-10: 0-321-61117-9 (v 2) Physics Textbooks I Wolfson, Richard II Title QC23.2.R49 2009 530 dc22 2009024991 ISBN 10: 0-321-61116-0; ISBN 13: 978-0-321-61116-1 (Student edition Volume 1) ISBN 10: 0-321-66665-8; ISBN 13: 978-0-321-66665-9 (Professional copy Volume 1) 10 CRK 13 12 11 10 09 Manfactured in the United States of America About the Authors Andrew F Rex Tad Merrick Andrew F Rex has been professor of physics at the University of Puget Sound since 1982 He frequently teaches the College Physics course, so he has a deep sense of student and instructor challenges He is the author of several textbooks, including Modern Physics for Scientists and Engineers and Integrated Physics and Calculus In addition to textbook writing, he studies foundations of the second law of thermodynamics, which has led to the publication of several papers and the widely acclaimed book Maxwell s Demon: Entropy, Information, Computing Richard Wolfson Richard Wolfson has been professor of physics at Middlebury College for more than 25 years In addition to his textbooks, Essential University Physics, Physics for Scientists and Engineers, and Energy, Environment, and Climate, he has written two science books for general audiences: Nuclear Choices: A Citizen s Guide to Nuclear Technology, and Simply Einstein: Relativity Demystified His video courses for the Teaching Company include Physics in Your Life and Einstein s Relativity and the Quantum Revolution: Modern Physics for Non-Scientists v Preface to the Instructor During the three decades we have been teaching physics, algebra-based physics textbooks have grown in length, complexity, and price We ve reached the point where textbooks can be overwhelming to students, many of whom are taking physics as a requirement for another major or profession and will never take another physics class And yet, we ve also seen many students in the algebra-based course who are eager to learn how physics explains what they see in their everyday lives, how it connects to other disciplines, and how exciting new ideas in physics can be A Concise and Focused Book The first thing you ll notice about this book is that it s more concise than most algebrabased textbooks We believe it is possible to provide a shorter, more focused text that better addresses the learning needs of today s students while more effectively guiding them through the mastery of physics The language is concise and engaging without sacrificing depth Brevity needn t come at the expense of student learning! We ve designed our text from the ground up to be concise and focused, rather than cutting down a longer book Students will find the resulting book less intimidating and easier to use, with well coordinated narrative, instructional art program, and worked examples A Connected Approach In addition to making the volume of the book less overwhelming, we ve stressed connections, to reinforce students understanding and to combat the preconception that physics is just a long list of facts and formulas Connecting ideas The organization of topics and the narrative itself stress the connections between ideas Whenever possible, the narrative points directly to a worked example or to the next section A worked example can serve as a bridge, not only to the preceding material it is being used to illustrate, but also forward by introducing a new idea that is then explicated in the following section These bridges work both ways; the text is always looking forward and back to exploit the rich trail of connections that exist throughout physics * * * * * * vi Complete edition Volumes (shrinkwrapped) (ISBN 978-0321-59854-7): Chapters 26 Volume (ISBN 978-0-32161116-1): Chapters 14 Volume (ISBN 978-0-32161117-8): Chapters 15 26 Complete edition Volumes (shrinkwrapped) with MasteringPhysicsTM (ISBN 978-0-32159856-1): Chapters 26 Volume with MasteringPhysicsTM (ISBN 978-0-32161118-5): Chapters 14 Volume with MasteringPhysicsTM (ISBN 978-0-32161119-2): Chapters 15 26 Connecting physics with the real world Instead of simply stating the facts of physics and backing them up with examples, the book develops some key concepts from observations of real-world phenomena This approach helps students to understand what physics is and how it relates to their lives In addition, numerous examples and applications help students explore the ideas of physics as they relate to the real world Connections are made to phenomena that will engage the students applications from everyday life (heating a home, the physics of flight, DVDs, hybrid vehicles, and many more), from biomedicine (pacemakers, blood flow, cell membranes, medical imaging), and from cutting-edge research in science and technology (superconductivity, nanotechnology, ultracapacitors) These applications can be used to motivate interest in particular topics in physics, or they might emerge from learning a new physics topic One thing leads to another What results is a continuous story of physics, seen as a seamless whole rather than an encyclopedia of facts to be memorized Connecting words and math In the same way, we stress the connections between the ideas of physics and their mathematical expression Equations are statements about physics sentences, really not magical formulae In algebra-based physics, it s important to stress the basics but not the myriad details that cloud the issues for those new to the subject We ve reduced the number of enumerated equations, to make the essentials clearer Preface to the Instructor Connecting with how students learn Conceptual worked examples and end-of-chapter problems are designed to help students explore and master the qualitative ideas developed in the text Some conceptual examples are linked with numerical examples that precede or follow them, linking qualitative and quantitative reasoning skills Follow-up exercises to worked examples ( Making the Connection ) prompt students to explore further, while Got It? questions (short concept-check questions found at the end of text sections) help ensure a key idea is grasped before the student moves on Students benefit from a structured learning path clear goals set out at the start, reinforcement of new ideas throughout, and a strategic summary to wrap up With these aids in place, students build a solid foundation of understanding We therefore carefully structure the chapters with learning goals, Reviewing new concepts reminders, and visual chapter summaries Connecting with how students use their textbook Many students find using a textbook to be a chore, either because English is not their first language or because their reading skills are weak or their time limited Even students who read with ease prefer their explanations lucid and brief, and they expect key information to be easy to find Our goal, therefore, is a text that is clear, concise, and focused, with easy-to-find reference material, tips, and examples The manageable size of the book makes it less intimidating to open and easier to take to class To complement verbal explanations in the text, the art program puts considerable information directly on the art in the form of explanatory labels and author s voice commentary Thus, students can use the text and art as parallel, complementary ways to understand the material The text tells them more, but often the illustrations will prove more memorable and will serve as keys for recalling information In addition, a student who has difficulty with the text can turn to the art for help Connecting the chapters with homework After reading a chapter, students need to be able to reason their way through homework problems with some confidence that they will succeed A textbook can help by consistently demonstrating and modeling how an expert goes about solving a problem, by giving clear tips and tactics, and by providing opportunities for practice Given how important it is for students to become proficient at solving problems, a detailed explanation of how our textbook will help them is provided below Problem-Solving Strategies Worked examples are presented consistently in a three-step approach that provides a model for students: Organize and Plan The first step is to gain a clear picture of what the problem is asking Then students gather information they need to address the problem, based on information presented in the text and considering similarities with earlier problems, both conceptual and numerical If a student sketch is needed to help understand the physical situation, this is the place for it Any known quantities that will be needed to calculate the answer or answers are gathered at the end of this step Solve The plan is put into action, and the required steps carried out to reach a final answer Computations are presented in enough detail for the student to see a clear path from start to finish Reflect There are many things that a student might consider here Most important is whether the answer is reasonable, in the context of either the problem or a similar known situation This is the place to see whether units are correct or to check that symbolic answers reduce to sensible results in obvious special cases The student may reflect on connections to other solved problems or real-life situations Sometimes solving a problem raises a new question, which can lead naturally to another example, the next section, or the next chapter Conceptual examples follow a simpler two-step approach: Solve and Reflect As with the worked examples, the Reflect step is often used to point out important connections vii viii Preface to the Instructor Worked examples are followed by Making the Connection, a new problem related to the one just solved, which serves as a further bridge to earlier material or the next section of text Answers to Making the Connection are provided immediately, and thus they also serve as good practice problems getting a second example for the price of one Strategy boxes follow the three-step approach that parallels the approach in worked examples These give students additional hints about what to in each of the three steps Tactic boxes give additional problem-solving tools, outside the three-step system End-of-Chapter Problems There are three types of problems: Conceptual questions, like the conceptual worked examples, ask the students to think about the physics and reason without using numbers Multiple-choice problems serve three functions First, they prepare students for their exams, in cases where instructors use that format Second, those students who take this course in preparation for the MCAT exam or other standardized exam will get some needed practice Third, they offer more problem-solving practice for all students Problems include a diversity of problem types, as well as a range of difficulty, with difficulty levels marked by one, two, or three boxes Problems are numerous enough to span an appropriate range of difficulty, from confidence builders to challenge problems Most problems are listed under a particular section number in the chapter General problems at the end are not tied to any section These problem sets include multi-concept problems that require using concepts and techniques from more than one section or from an earlier chapter Organization of Topics The organization of topics should be familiar to anyone who has taught College Physics The combined Volumes and cover a full-year course in algebra-based physics, divided into either two semesters or three quarters Volume 1: Following the introductory Chapter 1, the remainder of Volume is devoted to mechanics of particles and systems, including one chapter each on gravitation, fluids, and waves (including sound) Volume concludes with a three-chapter sequence on thermodynamics Volume 2: Volume begins with six chapters on electricity and magnetism, culminating and concluding with a chapter on electromagnetic waves and relativity Following this are two chapters on optics one on geometrical optics and one on wave optics The final four chapters cover modern physics, including quanta, atoms, nuclei, and elementary particles Instructor Supplements NOTE: For convenience, all of the following instructor supplements can also be downloaded from the Instructor Area, accessed via the left-hand navigation bar of MasteringPhysicsTM (www.masteringphysics.com) The Instructor Solutions Manual, written by Brett Kraabel, Freddy Hansen, Michael Schirber, Larry Stookey, Dirk Stueber, and Robert White, provides complete solutions to all the end-of-chapter questions and problems All solutions follow the Organize and Plan/Solve/Reflect problem-solving strategy used in the textbook for quantitative problems and the Solve/Reflect strategy for qualitative ones The solutions are available by chapter in Word and PDF format and can be downloaded from the Instructor Resource Center (www.pearsonhighered.com/educator) Preface to the Instructor The cross-platform Instructor Resource DVD (ISBN 978-0-321-61126-0) provides invaluable and easy-to-use resources for your class The contents include a comprehensive library of more than 220 applets from ActivPhysics OnLine , as well as all figures, photos, tables, and summaries from the textbook in JPEG format In addition, all the ProblemSolving Strategies, Tactics Boxes, and Key Equations are provided in editable Word as well as JPEG format PowerPoint slides containing all the figures from the text are also included, as well as Classroom Response Clicker questions MasteringPhysics (www.masteringphysics.com) is a homework, tutorial, and assessment system designed to assign, assess, and track each student s progress In addition to the textbook s end-of-chapter problems, MasteringPhysics for Essential College Physics also includes prebuilt assignments and tutorials MasteringPhysics provides instructors with a fast and effective way to assign uncompromising, wide-ranging online homework assignments of just the right difficulty and duration The tutorials coach 90% of students to the correct answer with specific wrong-answer feedback The powerful post-assignment diagnostics allow instructors to assess the progress of their class as a whole or to quickly identify individual students areas of difficulty ActivPhysics OnLine (accessed through the Self Study area within www.mastering physics.com) provides a comprehensive library of more than 420 tried and tested ActivPhysics applets updated for web delivery using the latest online technologies In addition, it provides a suite of highly regarded applet-based tutorials developed by education pioneers Professors Alan Van Heuvelen and Paul D Alessandris The ActivPhysics margin icon directs students to specific exercises that complement the textbook discussion The online exercises are designed to encourage students to confront misconceptions, reason qualitatively about physical processes, experiment quantitatively, and learn to think critically They cover all topics from mechanics to electricity and magnetism and from optics to modern physics The highly acclaimed ActivPhysics OnLine companion workbooks help students work through complex concepts and understand them more clearly More than 220 applets from the ActivPhysics OnLine library are also available on the Instructor Resource DVD The Test Bank contains more than 2000 high-quality problems, with a range of multiplechoice, true/false, short-answer, and regular homework-type questions Test files are provided in both TestGen® (an easy-to-use, fully networkable program for creating and editing quizzes and exams) and Word format, and can be downloaded from www.pearsonhighered.com/educator Student Supplements The Student Solutions Manuals Volume (Chapters 14) (ISBN 978-0-321-61120-8) and Volume (Chapters 15 26) (ISBN 978-0-321-61128-4), written by Brett Kraabel, Freddy Hansen, Michael Schirber, Larry Stookey, Dirk Stueber, and Robert White, provide detailed solutions to half of the odd-numbered end-of-chapter problems Following the problem-solving strategy presented in the text, thorough solutions are provided to carefully illustrate both the qualitative (Solve/Reflect) and quantitative (Organize and Plan/Solve/ Reflect) steps in the problem-solving process MasteringPhysics (www.masteringphysics.com) is a homework, tutorial, and assessment system based on years of research into how students work physics problems and precisely where they need help Studies show that students who use MasteringPhysics significantly increase their final scores compared to those using handwritten homework MasteringPhysics achieves this improvement by providing students with instantaneous feedback specific to their wrong answers, simpler sub-problems upon request when they get stuck, and partial credit for their method(s) used This individualized, 24/7 Socratic tutoring is recommended by nine out of ten students to their peers as the most effective and timeefficient way to study Pearson eText is available through MasteringPhysics, either automatically when MasteringPhysics is packaged with new books or as a purchased upgrade online Allowing students access to the text wherever they have access to the Internet, Pearson eText comprises ix x Preface to the Instructor the full text, including figures that can be enlarged for better viewing Within Pearson eText, students are also able to pop up definitions and terms to help with vocabulary and the reading of the material Students can also take notes in Pearson eText, using the annotation feature at the top of each page Pearson Tutor Services (www.pearsontutorservices.com) Each student s subscription to MasteringPhysics also contains complimentary access to Pearson Tutor Services, powered by Smarthinking, Inc By logging in with their MasteringPhysics ID and password, students will be connected to highly qualified e-instructors who provide additional, interactive online tutoring on the major concepts of physics Some restrictions apply; offer subject to change ActivPhysics OnLine (accessed via www.masteringphysics.com) provides students with a suite of highly regarded applet-based tutorials (see above) The following workbooks help students work though complex concepts and understand them more clearly The ActivPhysics margin icons throughout the book direct students to specific exercises that complement the textbook discussion ActivPhysics OnLine Workbook Volume 1: Mechanics Thermal Physics Oscillations & Waves (ISBN 978-0-805-39060-5) ActivPhysics OnLine Workbook Volume 2: Electricity & Magnetism Optics Modern Physics (ISBN 978-0-805-39061-2) Acknowledgments A new full-year textbook in introductory physics doesn t just happen overnight or by accident We begin by thanking the entire editorial and production staff at Pearson Education The idea for this textbook grew out of discussions with Pearson editors, particularly Adam Black, whose initial encouragement and vision helped launch the project; and Nancy Whilton, who helped hone and guide this text to its current essentials state Other Pearson staff who have rendered invaluable service to the project include Ben Roberts, Michael Gillespie, Development Manager; Margot Otway, Senior Development Editor; Gabriele Rennie, Development Editor; Mary Catherine Hagar, Development Editor; Martha Steele; Senior Project Editor; and Claudia Trotch, Editorial Assistant In the project s early days, we were bolstered by many stimulating discussions with Jon Ogborn, whose introductory textbooks have helped improve physics education in Great Britain In addition to the reviewers mentioned below, we are grateful to Charlie Hibbard, accuracy checker, for his close scrutiny of every word, symbol, number, and figure; to Sen-Ben Liao for meticulously solving every question and problem and providing the answer list; and to Brett Kraabel, Freddy Hansen, Michael Schirber, Larry Stookey, Dirk Stueber, and Robert White for the difficult task of writing the Instructor Solutions Manual We also want to thank production supervisors Nancy Tabor and Shannon Tozier for their enthusiasm and hard work on the project; Jared Sterzer and his colleagues at Pre-Press PMG for handling the composition of the text; and Kristin Piljay, photo researcher Andrew Rex: I wish to thank my colleagues at the University of Puget Sound, whose support and stimulating collegiality I have enjoyed for almost 30 years The university s staff, in particular Neva Topolski, has provided many hours of technical support throughout this textbook s development Thanks also to student staff member Dana Maijala for her technical assistance I acknowledge all the students I have taught over the years, especially those in College Physics classes Seeing how they learn has helped me generate much of what you see in this book And last but foremost, I thank my wife Sharon for her continued support, encouragement, and amazing patience throughout the length of this project Richard Wolfson: First among those to be acknowledged for their contributions to this project are the thousands of students in my introductory physics courses over three decades at Middlebury College You ve taught me how to convey physics ideas in many different ways appropriate to your diverse learning styles, and your enthusiasm has convinced me that physics really can appeal to a wide range of students for whom it s not their primary interest Thanks also to my Middlebury faculty colleagues and to instructors around the ... Information, Computing Richard Wolfson Richard Wolfson has been professor of physics at Middlebury College for more than 25 years In addition to his textbooks, Essential University Physics, Physics for... 46 67 251 312 406 429 484 492 ii Essential COLLEGE PHYSICS FIRST EDITION Volume Chapters 14 Andrew F Rex Richard Wolfson University of Puget Sound Middlebury College Addison-Wesley Publisher:... Congress Cataloging-in-Publication Data Rex, Andrew F., 195 6Essential college physics / Andrew F Rex, Richard Wolfson 1st ed p cm Includes index ISBN-13: 978-0-321-61116-1 (v 1) ISBN-10: 0-321-61116-0