| Preface |

We have written this text for students and teachers who are partners in a one-year algebra-based physics course. The single most important pedagogical issue in this course is the synergistic relationship between conceptual understanding and problem solving; we have substantially strengthened this relationship in the seventh edition. Our efforts were helped immeasurably by the many insights and suggestions provided by users of the sixth edition, as well as by the work of physics-education researchers. In taking a fresh look at the text, we have added new features and material, refined areas in need of improvement, and worked toward an even greater clarity in the design of the book.

Goals

Conceptual Understanding Helping students develop a conceptual understanding of physics principles is a primary goal of this text. This is a challenging task, because physics is often regarded as a collection of equations that can be used blindly to solve problems. However, a good problem-solving technique does not begin with equations. It starts with a firm grasp of the concepts and how they fit together to provide a coherent description of the physical world. The features in the text that work toward this goal are Check Your Understanding questions, Self-Assessment Tests (an online feature), Concept Simulations (an online feature), Concepts & Calculations sections, Conceptual Examples, and Concepts-at-a-Glance charts.
Reasoning The ability to reason in an organized manner is essential to solving problems, and helping students to improve their reasoning ability is also one of our primary goals. To this end, we have included examples that focus on Analyzing Multiple-Concept Problems (a new feature), the homework problems at the end of each chapter (a new interactive, online feature), Interactive LearningWare (an online tutorial that steps students through 60 different examples), Interactive Solutions (111 online solutions that explore the reasoning pertinent to certain homework problems), explicit reasoning steps in all examples, and Reasoning Strategies that summarize the logical steps involved in solving certain classes of problems. A strong reasoning ability, combined with firm conceptual understanding, is the legacy that we wish to leave to our students.
Relevance Finally, we want to show students that physics principles come into play over and over again in their lives. It is always easier to learn something new if it is directly related to day-to-day living. Direct applications of physics principles are identified in the margin or in the text by the label The Physics of…. Many of these applications are biomedical in nature and deal with human physiology. Other applications, such as CDs and DVDs and digital photography, deal with modern technology. Still others deal with things that we take for granted in our lives, such as household plumbing. We have also incorporated real-world situations into many of the worked-out examples and the homework material at the end of each chapter.

Organization and Coverage

The text consists of 32 chapters and is organized in a fairly standard fashion according to the following sequence: Mechanics, Thermal Physics, Wave Motion, Electricity and Magnetism, Light and Optics, and Modern Physics. The text is available in two formats: in a complete volume, consisting of all 32 chapters, and in two volumes (Chapters 1 - 17 and Chapters 18 - 32). Chapter sections marked with an asterisk(*) can be omitted with little impact on the overall development of the material.
Based on feedback from users and reviewers, we have made judicial deletions and revised other material. In particular, a number of the examples have been modified to improve clarity and present topics of current interest. We have also updated our applications of physics principles and added twenty new ones, of which eleven are biomedical in nature. In addition, we have increased the number of homework problems that are of biological interest.
For instructors who wish to cover surface tension, we have included a module on our Web site (www.wiley.com/college/cutnell). This module discusses the nature of surface tension, capillary action, and the pressure inside a soap bubble and a liquid drop. Homework problems are also included for assignment.

Multimedia Version of The Seventh Edition

THE MULTIMEDIA BOOK This hypertext version of the text is linked to the Study Guide, the Student Solutions Manual, the Self-Assessment Tests, the Interactive Learning-Ware, the Interactive Solutions, the Concept Simulations, and other multimedia. The Multimedia Book can be used by students in many ways, but it is preeminently a very powerful study aid. The algebra-based introductory physics course is a problem-solving course, and the Multimedia Book provides more problem-solving help than any other source available.
WileyPLUS(formerly eGrade Plus) By combining two powerful Web-based programs—WileyPLUS and the Multimedia Book—we can offer physics teachers and physics students a unique teaching and learning environment.
Helping Teachers Teach: WileyPLUS is a homework management system that allows the teacher to assign, collect, and grade homework automatically. WileyPLUS keeps the students “on task” without the teacher having to invest hours every week grading homework.
Helping Students Learn: All problems assigned in WileyPLUS have a link to an online version of the complete text and the associated student supplements. The links give the students quick access to focused problem-solving help. Context-sensitive help—just a click away. Those problems marked with the icon are presented in a guided tutorial format that provides enhanced interactivity.

Features of The Seventh Edition

ANALYZING MULTIPLE-CONCEPT PROBLEMS: A New Format for Examples One of the main goals of physics instruction is to help students develop the ability to solve problems that are more thought-provoking than the typical “plug-and-chug” problems. These more sophisticated problems involve two or more physics concepts, and are generally known as “multiple-concept” problems.
The challenge for students is first to identify the physics concepts involved in such a problem, then to associate with each concept an appropriate mathematical equation, and finally to assemble the equations to produce a unified algebraic solution.
The Analyzing Multiple-Concept Problems feature presents examples in a step-by-step format that relies heavily on visualization. The feature builds a visual bridge between each physics concept involved in the solution and the mathematical evolution of that solution.
In order to reduce a complex problem into a sum of simpler parts, each Multiple-Concept example consists of four sections: Reasoning, Knowns and Unknowns, Modeling the Problem, and Solution:
Reasoning When students begin to solve a complex problem, it is essential that they have a general idea of where they’re going. The Reasoning section discusses the strategy that will be used to solve the problem. This section presents an overview of the physics concepts employed in the solution, but largely without mathematical equations.
Knowns and Unknowns In this stage all the pertinent data are assembled. This step is crucial, because the data provide important clues about how to proceed with the solution. Each known variable in the problem is given a verbal description, an algebraic symbol, and a numerical value. Assigning algebraic symbols is important, because the solution is constructed using these symbols; the numerical solution is obtained only after the algebraic solution is complete. Both explicit data and implicit data are identified. Students often overlook data that are present implicitly in the verbal statement of the problem and focus only on explicitly stated numerical values.
Modeling the Problem This stage, which consists of a two-column table, lies at the heart of the Multiple-Concept examples. In the left column are the individual steps used in solving the problem . Each step explains why a particular concept is used, and the step also identifies the mathematical equation that represents the concept.
In the right column, the mathematical model for the problem as a whole is evolved . As each step in the left column is presented, the mathematical result of that step is incorporated in the right column into the results from the previous steps. This is done in a highly visual manner, so students can see readily how the individual mathematical equations fit together to produce the desired result. With this method, the algebraic solution to the problem emerges in a logical, easy-to-understand manner.
Solution This part of the example takes the algebraic equations developed in the Modeling-the-Problem section and assembles them into an algebraic solution for the problem. Then, the data from the Knowns-and-Unknowns section is in serted to produce a numerical solution.
At the end of each Multiple-Concept example, a number of related homework problems are identified. These problems contain concepts similar to those in the Multiple-Concept example.

PROBLEMS This feature is based on the homework maerial found at the end of each chapter under the heading “Concepts & Calculations.” Each of these 236 problems consists of a series of concept questions and related quantitative calculations, a structure that is intended to help students incorporate concept identification into their problem-solving methodology. All of the problems have been made available for assignment via an online homework management program such as WileyPLUS or WebAssign. In this online mode, the problems are presented in a guided tutorial format that provides enhanced interactivity in a variety of ways.
Concept Questions These are presented in a multiple-choice format that provides feedback for both correct and incorrect student responses, along with hyperlinks to the relevant sections in the online version of the complete text. The ordering of the various answer choices is randomized on an individual student basis.

Quantitative Calculations These are designed to help the student organize an analytical approach to arriving at the correct answer. In preparation for the calculations that are ultimately required, the student is asked to input algebraic expressions for various quantities. The nature of these expressions varies from problem to problem. In the simpler cases, the student is asked immediately for the algebraic expression that is used to determine the final answer and is then prompted for the associated numerical answer. In more difficult problems, the student is required to input a number of basic algebraic expressions that relate to the concepts central to the problem and may be asked to calculate intermediate results. When appropriate, the student is then asked to combinethe basic expressions and produce a final algebraic solution to the problem. Hyperlinks to relevant text examples are provided where appropriate. Finally, the numerical answer is requested.
Units Using correct units is an important part of a problem-solving technique that is often overlooked in homework assignments. To keep students focused on the physical quantities about which they are being questioned, they are always asked to select the proper measurement unit when inputting numerical answers.

APPLICATIONS OF PHYSICS PRINCIPLES Many applications of physics principles that are new to the text have been added. Roughly half of these are in the medical area, which is of especial interest to many students in health-related professions. For example, the widely used body mass index is analyzed from the point of view of unit conversions. The technique known as rapid thermal exchange is showing great promise for treating the effects of overheating on the human body; it utilizes forced convection. An ultrasonic probe called an A-scan is used to measure the distances that facilitate the design of lens implants used in cataract surgery; how the A-scan makes these measurements is discussed. Transcutaneous electrical nerve stimulation is the most commonly used form of electroanalgesia for pain management; it depends on the ability of weak ac electricity to inhibit pain-related nerve impulses. Brachytherapy implants allow radioactive isotopes to be used in cancer treatments and in the treatment of atherosclerosis in a way that minimizes damage to healthy tissue.
The remaining new applications deal with a wide variety of situations. For example, the effect of the static stability factor in rollover of SUVs is discussed in the context of the center of gravity. The operation of the joystick familiar to computer game enthusiasts is described in terms of resistors wired in series. The operation of body-fat scales is presented as an example of the use of bioelectric impedance analysis to measure body-fat percentage. How certain butterflies utilize polarized light in attracting mates is discussed. And how a laser altimeter is used to construct three-dimensional topographical maps is described.
VECTOR NOTATION One of the standard methods for representing vector quantities is to use boldface symbols (e.g., F), and we have followed this procedure throughout earlier editions of the text. However, in response to requests from teachers and students alike, we now represent each vector quantity as a boldface symbol with an arrow above it (e.g., ). This alternative notation has the advantage of being consistent with the practice followed by teachers giving lectures and by students taking notes.
CHECK YOUR UNDERSTANDING This feature consists of 130 questions found at key locations throughout the text. Each is a carefully selected question that is designed to test a student’s understanding of the concepts. The questions are in either a multiple-choice or free-response format, and the answers are provided at the end of the book.

SELF-ASSESSMENT TESTS The Self-Assessment Tests are online tests (www.wiley.com/college/cutnell) that are linked directly to specific sections of the book. There are about two Self-Assessment Tests per chapter, each containing 8–10 questions and problems. The tests are designed so that students, after studying the designated sections, can immediately assess their understanding of the material. Each contains thought-provoking conceptual questions, like the Check-Your-Understanding questions, as well as calculational problems. The Self-Assessment Tests are user-friendly, for they can be taken as often as the student wishes, and they provide extensive feedback in the form of helpful hints and suggestions when incorrect answers are selected.
CONCEPT SIMULATIONS Often, many concepts in physics—such as relative velocities, collisions, and ray tracing—can be better understood when they are simulated. Available online (www.wiley.com/college/cutnell) are 61 simulations, with which the student can experiment, since one or more parameters are under user control. Many of the simulations are directly related to homework material and are specifically referenced in that material, as well as in the chapter-ending summaries.
CONCEPT SUMMARIES All chapter-ending summaries present an abridged, but complete, version of the material on a section-by-section basis, including important equations. To help students review the material, the discussion of each section is flanked by two lists. On one side, a list of topics provides a quick-reference option for locating a given topic. On the other side, a color-coded list of the text examples and the online learning aids (Concept Simulations, Interactive LearningWare, and Interactive Solutions) shows students the additional help that is available. The summary also identifies the online Self-Assessment Tests that are keyed to the sections, so that students can evaluate their understanding of the chapter topics.
INTERACTIVE SOLUTIONS Often, students experience difficulty in getting started with the more difficult homework problems. The Interactive Solutions feature consists of 111 online problems (www.wiley.com/college/cutnell), each of which is allied with a particular homework problem in the text. Each Interactive Solution is worked out by the student in an interactive manner, and the solution is designed to serve as a model for the associated homework problem. Those homework problems that are associated with Interactive Solutions are identified in the text.
CONCEPTS & CALCULATIONS Conceptual understanding is an essential part of a good problem-solving technique. To emphasize the role of conceptual understanding, every chapter includes a Concepts & Calculations section. These sections are organized around a special type of example, each of which begins with several conceptual questions that are answered before the quantitative problem is worked out. The purpose of the questions is to put into sharp focus the concepts with which the problem deals. We hope that these examples also provide mini-reviews of material studied earlier in the chapter and in previous chapters.

CONCEPTUAL EXAMPLES A good problem-solving technique begins with a foundation of conceptual understanding. Therefore, every chapter includes examples that are entirely conceptual in nature. These examples are worked out in a rigorous but qualitative fashion, with no (or very few) equations. Our intent is to provide students with explicit models of how to “think through” a problem before attempting to solve it numerically. The Conceptual Examples deal with a wide range of topics and a large number of issues that often confuse students. Wherever possible, we have focused on real-world situations and have structured the examples so that they lead naturally to homework material found at the ends of the chapters. The related homework material is explicitly identified, and that material contains a cross reference that encourages students to review the pertinent Conceptual Example.
INTERACTIVE LEARNINGWARE This feature consists of interactive calculational examples presented on our Web site (www.wiley.com/college/cutnell). References to the LearningWare are contained in nearly every chapter. Each example is designed in an interactive format that consists of five steps. We believe that these steps are essential to the development of problem-solving skills and that students will benefit from seeing them explicitly identified in each example.

1. | Visualization: Animations and drawings help students understand the situation.
2. | Reasoning: Multiple-choice questions and answers establish the conceptual basis for the solution.
3. | Knowns and Unknowns: The pertinent variables and the symbols for them are presented interactively in tables that evolve as the example proceeds.
4. | Modeling: The student models the problem with equations from the text.
5. | Solution: The solution to the problem is obtained.

The hallmark of these examples is a user-friendly clarity that allows the student to see how conceptual understanding and quantitative analysis work together in a problem-solving environment. Related homework material is identified and contains a cross-reference to the LearningWare.
EXPLICIT REASONING STEPS Since reasoning is the cornerstone of problem solving, we believe that students will benefit from seeing the reasoning stated explicitly. Therefore, the format in which examples are worked out includes an explicit reasoning step. In this step we explain what motivates our procedure for solving the problem before any algebraic or numerical work is done. In the Concepts & Calculations examples, the reasoning is presented in a question-and-answer format.
REASONING STRATEGIES A number of the examples in the text deal with well-defined strategies for solving certain types of problems. In such cases, we have included summaries of the steps involved. These summaries, which are titled Reasoning Strategies, encourage frequent review of the techniques used and help students focus on the related concepts.

CONCEPTS AT A GLANCE To provide a coherent picture of how new concepts are built upon previous ones and to reinforce fundamental unifying ideas, the text includes Concepts-at-a-Glance flowcharts. These charts show in a visual way the conceptual development of physics principles. Within a chart, new concepts are placed in gold panels, and previously introduced and related concepts are placed in light blue panels. Each chart is discussed in a separate and highlighted paragraph that helps students connect the new concept with the real world.

THE PHYSICS OF This edition contains 258 real-world applications that reflect our commitment to showing students how prevalent physics is in their lives. Each application is identified in the margin or in the text with the label The physics of, and those that deal with bio-medical material are further marked with an icon in the shape of a caduceus. A complete list of the applications can be found after the Table of Contents.

The physics of transcutaneous electrical nerve stimulation.

PROBLEM SOLVING INSIGHTS To reinforce the problem-solving techniques illustrated in the worked-out examples, we have included short statements in the margins or in the text, identified by the label Problem solving insight. These statements help students to develop good problem-solving skills by providing the kind of advice that a teacher gives when explaining a calculation in detail.

Problem solving insight “Implicit data” are important. For instance, in Example 6 the phrase “starting from rest” means that the initial velocity is zero.

HOMEWORK PROBLEMS AND CONCEPTUAL QUESTIONS Most of the homework problems in the seventh edition are available for assignment via an online homework management program such as WileyPLUS or WebAssign. In these programs the problems marked with the icon are presented in a guided tutorial format that provides enhanced interactivity. Of the large amount of homework material provided, roughly 300 are new or modified. In all of the homework, we have used a wide variety of real-world situations with realistic data. Those problems and questions marked with a caduceus deal with biomedical situations, and we have made a special effort to increase the amount of this type of homework material. The problems are ranked according to difficulty, with the most difficult problems marked with a double asterisk (**) and those of intermediate difficulty marked with a single asterisk (*). The easiest problems are unmarked. Problems and Conceptual Questions whose solutions appear in the Student Solutions Manual are identified with the label ssm. Those whose solutions are available on the Web (www.wiley.com/college/cutnell) are marked with the label www. Since teachers sometimes want to assign homework without identifying a particular section, we have provided a group of problems without reference to section under the heading Additional Problems. The problems under the heading Concepts & Calculations are modeled on the examples in the Concepts & Calculations section found at the end of each chapter and consist of a series of concept questions followed by a related quantitative problem. The questions are designed to help students identify the concepts that are used in solving the problem.
In spite of our best efforts to produce an error-free book, errors no doubt remain. They are solely our responsibility, and we would appreciate hearing of any that you find. We hope that this text makes learning and teaching physics easier and more enjoyable and look forward to hearing about your experiences with it. Please feel free to write us care of Physics Editor, Higher Education Division, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030 or contact us at www.wiley.com/college/cutnell

Copyright © 2007 John Wiley & Sons, Inc. All rights reserved.