Physics II For Dummies E-Book

Steven Holzner

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch
• Veröffentlichungsjahr: 2010

Seitenzahl: 503

Beschreibung

A plain-English guide to advanced physics Does just thinking about the laws of motion make your head spin? Does studying electricity short your circuits? Physics II For Dummies walks you through the essentials and gives you easy-to-understand and digestible guidance on this often intimidating course. Thanks to this book, you don?t have to be Einstein to understand physics. As you learn about mechanical waves and sound, forces and fields, electric potential and electric energy, and much more, you?ll appreciate the For Dummies law: The easier we make it, the faster you?ll understand it! * An extension of the successful Physics I For Dummies * Covers topics in a straightforward and effective manner * Explains concepts and terms in a fast and easy-to-understand way Whether you?re currently enrolled in an undergraduate-level Physics II course or just want a refresher on the fundamentals of advanced physics, this no-nonsense guide makes this fascinating topic accessible to everyone.

Leseprobe

Physics II For Dummies®

by Steven Holzner, PhD

Physics II For Dummies®

Published byWiley Publishing, Inc.111 River St.Hoboken, NJ 07030-5774www.wiley.com

Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana

Published simultaneously in Canada

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Library of Congress Control Number: 2010926836

ISBN: 978-0-470-53806-7

Manufactured in the United States of America

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About the Author

Steven Holzner taught Physics at Cornell University for more than a decade, teaching thousands of students. He’s the award-winning author of many books, including Physics For Dummies, Quantum Physics For Dummies, and Differential Equations For Dummies, plus For Dummies workbooks for all three titles. He did his undergraduate work at MIT and got his PhD from Cornell, and he has been on the faculty of both MIT and Cornell.

Dedication

To Nancy, of course.

Author’s Acknowledgments

The book you hold in your hands is the product of many people’s work. I’d particularly like to thank Acquisitions Editor Tracy Boggier, Senior Project Editor Alissa Schwipps, Senior Copy Editor Danielle Voirol, Technical Editors Laurie Fuhr and Ron Reifenberger, and the many talented folks in Composition Services.

Publisher’s Acknowledgments

We’re proud of this book; please send us your comments at http://dummies.custhelp.com. For other comments, please contact our Customer Care Department within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax [phone].

Some of the people who helped bring this book to market include the following:

Acquisitions, Editorial, and Media Development

Senior Project Editor: Alissa Schwipps

Acquisitions Editor: Tracy Boggier

Senior Copy Editor: Danielle Voirol

Contributor:

Introduction

For many people, physics holds a lot of terror. And Physics II courses do introduce a lot of mind-blowing concepts, such as the ideas that mass and energy are aspects of the same thing, that light is just a mix of electric and magnetic fields, and that every electron zipping around an atom creates a miniature magnet. In Physics II, charges jump, light bends, and time stretches — and not just because your instructor lost the class halfway through the lecture. Throw some math into the mix, and physics seems to get the upper hand all too often. And that’s a shame, because physics isn’t your enemy — it’s your ally.

The ideas may have come from Albert Einstein and other people who managed to get laws and constants and units of measurement named after them, but you don’t have to be a genius to understand Physics II. After all, it’s only partially rocket science — and those are ultra-cool, nearing-the-speed-of-light rockets.

Many breakthroughs in the field came from students, researchers, and others who were simply curious about their world, who did experiments that often didn’t turn out as expected. In this book, I introduce you to some of their discoveries, break down the math that describes their results, and give you some insight into how things work — as physicists understand it.

About This Book

Physics II For Dummies is for the inquiring mind. It’s meant to explain hundreds of phenomena that you can observe all around you. For example, how does polarized light really work? Was Einstein really right about time dilation at high speeds? Why do the electromagnets in electric motors generate magnetism? And if someone hands you a gram of radioactive material with a half-life of 22,000 years, should you panic?

To study physics is to study the world. Your world. That’s the kind of perspective I take in this book. Here, I try to relate physics to your life, not the other way around. So in the upcoming chapters, you see how telescopes and microscopes work, and you find out what makes a properly cut diamond so brilliant. You discover how radio antennas pick up signals and how magnets make motors run. You see just how fast light and sound can travel, and you get an idea of what it really means for something to go radioactive.

When you understand the concepts, you see that the math in physics isn’t just a parade of dreadful word problems; it’s a way to tie real-world measurements to all that theory. Rest assured that I’ve kept the math in this book relatively simple — the equations don’t require any knowledge beyond algebra and trigonometry.

Physics II For Dummies picks up where a Physics I course leaves off — after covering laws of motion, forces, energy, and thermodynamics. Physics I and Physics II classes have some overlap, so you do find info on electricity and magnetism in both this book and in Physics For Dummies. But in Physics II For Dummies, I cover these topics in more depth.

A great thing about this book is that you decide where to start and what to read. It’s a reference you can jump into and out of at will. Just head to the table of contents or the index to find the information you want.

Conventions Used in This Book

Some books have a dozen stupefying conventions that you need to know before you can start reading. Not this book. All you need to know is the following:

New terms are given in italics, like this, and are followed by a definition.

Variables, like m for mass, are in italics. If you see a letter or abbreviation in a calculation and it isn’t italicized, you’re looking at a unit of measurement; for instance, 2.0 m is 2.0 meters.

Vectors — those items that have both a magnitude and a direction — are given in bold, like this: B.

And those are all the conventions you need to know!

What You’re Not to Read

Besides the main text of the book, I’ve included some extra little elements that you may find enlightening or interesting: sidebars and paragraphs marked with Technical Stuff icons. The sidebars appear in shaded gray boxes, and they give you some nice little examples or tell stories that add a little color or show you how the main story of physics branches out. The Technical Stuff paragraphs give you a little more technical information on the matter at hand. You don’t need this to solve problems; you may just be curious.

If you’re in a rush, you can skip these elements without hurting my feelings. Without them, you still get the main story.

Foolish Assumptions

In this book, I assume the following:

You’re a student who’s already familiar with a Physics I text like Physics For Dummies. You don’t have to be an expert. As long as you have a reasonable knowledge of that material, you’ll be fine here. You should understand ideas such as mass, velocity, force, and so on, even if you don’t remember all the formulas.

You’re familiar with the metric system, or SI (the International System of Units). You can convert between units of measurement, and you understand how to use metric prefixes. I include a review of working with measurements in Chapter 2.

You know basic algebra and trigonometry. I tell you what you need in Chapter 2, so no need to worry. This book doesn’t require any calculus, and you can do all the calculations on a standard scientific calculator.

How This Book Is Organized

Like physics itself, this book is organized into different parts. Here are the parts and what they’re all about.

Part I: Understanding Physics Fundamentals

Part I starts with an overview of Physics II, introducing the goals of physics and the main topics covered in a standard Physics II course. This part also brings you up to speed on the basics of Physics I — just what you need for this book. You can’t build without a foundation, and you get the foundation you need here.

Part II: Doing Some Field Work: Electricity and Magnetism

Electricity and magnetism are a big part of Physics II. Over the years, physicists have done a great job of explaining these topics. In this part, you see both electricity and magnetism, including info on individual charges, AC (alternating current) circuits, permanent magnets, and magnetic fields — and perhaps most importantly, you see how electricity and magnetism connect to create electromagnetic waves (as in light).

Part III: Catching On to Waves: The Sound and Light Kinds

This part covers waves in general, as well as light and sound waves. Of the two, light is the biggest topic — you see how light waves interact and interfere with each other, as well as how they manage when going through single and double slits, bouncing off objects, passing through glass and water, and doing all kinds of other things. The study of optics includes real-world objects such as lenses, mirrors, cameras, polarized sunglasses, and more.

Part IV: Modern Physics

This part brings you into the modern day with the theory of special relativity, the particle-wave duality of matter, and radioactivity. Relativity is a famous one, of course, and you see a lot of Einstein in this part. You also see many other physicists who chipped in on the discussion of matter’s travels as waves. You read all about radioactivity and atomic structure, too.

Part V: The Part of Tens

The chapters in this part cover ten topics in rapid succession. You take a look at ten physics experiments that changed the world, leading to discoveries in everything from special relativity to radioactivity. You also look at ten online calculators that can assist you in solving physics problems.

Icons Used in This Book

You find icons in this book, and here’s what they mean:

This icon marks something to remember, such as a law of physics or a particularly important equation.

Tips offer ways to think of physics concepts that can help you better understand a topic. They may also give you tips and tricks for solving problems.

This icon means that what follows is technical, insider stuff. You don’t have to read it if you don’t want to, but if you want to become a physics pro (and who doesn’t?), take a look.

Where to Go from Here

In this book, you can jump in anywhere you want. You can start with electricity or light waves or even relativity. But if you want the full story, start with Chapter 1. It’s just around the corner from here. Happy reading!

If you don’t feel comfortable with the level of physics taken for granted from Physics I, check out a Physics I text. I can recommend Physics For Dummies wholeheartedly.

Part I

Understanding Physics Fundamentals

In this part . . .

In this part, you make sure you’re up to speed on the skills you need for Physics II. You start with an overview of the topics I cover in this book. You also review Physics I briefly, making sure you have a good foundation in the math, measurements, and main ideas of basic physics.

Part II

Doing Some Field Work: Electricity and Magnetism

In this part . . .

Physicists have long been friends with electricity and magnetism. In this part, you see all about electric field, charges, the force between charges, electric potential, and more. You also explore magnetism, such as the magnetic field from a wire, the force between two wires, how charged particles orbit in magnetic fields, and the like. And you look at AC circuits, in which magnetic and electric fields work together to regenerate the current.

Chapter 3

Getting All Charged Up with Electricity

In This Chapter

Understanding charges

Examining electric forces and Coulomb’s law

Finding electric field

Finding electric potential

Understanding electric potential and capacitors

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