Physics (5th Edition) + Solution

Book Preface

What’s the Big Idea?

James Walker’s Physics, Fifth Edition engages students by connecting conceptual and quantitative physics to the world around them, making complex concepts understandable, and helping students build problem-solving skills. New “just in time” learning aids, such as the “Big Ideas,” quickly orient students to the overarching principles of each chapter, while new Real-World Physics and Biological Applications expose students to physics they can observe in their own lives. A revised problem-solving pedagogy allows students to build a deep understanding of the relationship between the conceptual and the quantitative.

The goal of physics is to gain a deeper understanding of the world in which we live. For example, the laws of physics allow us to predict the behavior of everything from rockets sent to the Moon, to integrated chips in computers, to lasers used to perform eye surgery. In short, everything in nature—from atoms and subatomic particles to solar systems and galaxies— obeys the laws of physics. In this chapter, we develop a common “language” of physics that will be used throughout this book.

Physics is the study of the fundamental laws of nature, which, simply put, are the laws that underlie all physical phenomena in the universe. Remarkably, we have found that these laws can be expressed in terms of mathematical equations. As a result, it is possible to make precise, quantitative comparisons between the predictions of theory—derived from the mathematical form of the laws—and the observations of experiments. Physics, then, is a science rooted equally firmly in both theory and experiment. As physicists make new observations, they constantly test and—if necessary— refine the present theories.

What makes physics particularly fascinating is the fact that it relates to everything in the universe. There is a great beauty in the vision that physics brings to our view of the universe—namely, that all the complexity and variety that we see in the world around us, and in the universe as a whole, are manifestations of a few fundamental laws and principles. That we can discover and apply these basic laws of nature is both astounding and exhilarating.

For those not familiar with the subject, physics may seem to be little more than a confusing mass of formulas. Sometimes, in fact, these formulas can be the trees that block the view of the forest. For a physicist, however, the many formulas of physics are simply different ways of expressing a few fundamental ideas. It is the forest—the basic laws and principles of physical phenomena in nature—that is the focus of this text.