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Welcome to Understanding Physics (page one).This book is built on the foundations of the 6th Edition of Halliday, Resnick, and Walker’s Fundamentals of Physics which we often refer to as HRW 6th. The HRW 6th text and its ancestors, first written by David Halliday and Robert Resnick, have been best-selling introductory physics texts for the past 40 years. It sets the standard against which many other texts are judged.You are probably thinking, “Why mess with success?” Let us try to explain.
Why a Revised Text? A physics major recently remarked that after struggling through the first half of his junior level mechanics course, he felt that the course was now going much better. What had changed? Did he have a better background in the material they were covering now? “No,” he responded. “I started reading the book before every class. That helps me a lot. I wish I had done it in Physics One and Two.” Clearly, this student learned something very important. It is something most physics instructors wish they could teach all of their students as soon as possible. Namely, no matter how smart your students are, no matter how well your introductory courses are designed and taught, your students will master more physics if they learn how to read an “understandable” textbook carefully. We know from surveys that the vast majority of introductory physics students do not read their textbooks carefully. We think there are two major reasons why: (1) many students complain that physics textbooks are impossible to understand and too abstract, and (2) students are extremely busy juggling their academic work, jobs, personal obligations, social lives and interests. So they develop strategies for passing physics without spending time on careful reading.We address both of these reasons by making our revision to the sixth edition of Fundamentals of Physics easier for students to understand and by providing the instructor with more Reading Exercises (formerly known as Checkpoints) and additional strategies for encouraging students to read the text carefully. Fortunately, we are attempting to improve a fine textbook whose active author, Jearl Walker, has worked diligently to make each new edition more engaging and understandable.
In the next few sections we provide a summary of how
we are building upon HRW 6th and shaping it into this new textbook.
A Narrative That Supports Student Learning
One of our primary goals is to help students make sense of the
physics they are learning. We cannot achieve this goal if students
see physics as a set of disconnected mathematical equations that
each apply only to a small number of specific situations. We stress
conceptual and qualitative understanding and continually make connections
between mathematical equations and conceptual ideas.We also try
to build on ideas that students can be expected to already understand,
based on the resources they bring from everyday experiences.
In Understanding Physics we have tried to tell a story that flows
from one chapter to the next. Each chapter begins with an introductory
section that discusses why new topics introduced in the chapter
are important, explains how the chapter builds on previous chapters,
and prepares students for those that follow.We place explicit emphasis
on basic concepts that recur throughout the book. We use extensive
forward and backward referencing to reinforce connections between
topics. For example, in the introduction of Chapter 16 on Oscillations
we state: “Although your study of simple harmonic motion will
enhance your understanding of mechanical systems it is also vital
to understanding the topics in electricity and magnetism encountered
in Chapters 30-37. Finally, a knowledge of SHM provides a basis
for understanding the wave nature of light and how atoms and nuclei
absorb and emit energy.”
Emphasis on Observation and Experimentation Observations and concrete everyday experiences are the starting points for development of mathematical expressions. Experiment-based theory building is a major feature of the book.We build ideas on experience that students either already have or can easily gain through careful observation. Whenever possible, the physical concepts and theories developed in Understanding Physics grow out of simple observations or experimental data that can be obtained in typical introductory physics laboratories. We want our readers to develop the habit of asking themselves:What do our observations, experiences and data imply about the natural laws of physics? How do we know a given statement is true? Why do we believe we have developed correct models for the world? Toward this end, the text often starts a chapter by describing everyday observations with which students are familiar.This makes Understanding Physics a text that is both relevant to students’ everyday lives and draws on existing student knowledge. We try to follow Arnold Arons’ principle “idea first, name after.” That is, we make every attempt to begin a discussion by using everyday language to describe common experiences. Only then do we introduce formal physics terminology to represent the concepts being discussed. For example, everyday pushes, pulls, and their impact on the motion of an object are discussed before introducing the term “force” or Newton’s Second Law. We discuss how a balloon shrivels when placed in a cold environment and how a pail of water cools to room temperature before introducing the ideal gas law or the concept of thermal energy transfer. The “idea first, name after” philosophy helps build patterns of association between concepts students are trying to learn and knowledge they already have. It also helps students reinterpret their experiences in a way that is consistent with physical laws. Examples and illustrations in Understanding Physics often present data from modern computer-based laboratory tools. These tools include computer-assisted data acquisition systems and digital video analysis software. We introduce students to these tools at the end of Chapter 1. Examples of these techniques are shown in Figs. P-1 and P-2 (on the left) and Fig. P-3 on the next page. Since many instructors use these computer tools in the laboratory or in lecture demonstrations, these tools are part of the introductory physics experience for more and more of our students. The use of real data has a number of advantages. It connects the text to the students’ experience in other parts of the course and it connects the text directly to real world experience. Regardless of whether data acquisition and analysis tools are used in the student’s own laboratory, our use of realistic rather that idealized data helps students develop an appreciation of the role that data evaluation and analysis plays in supporting theory. |
