AP* Physics 1 Essentials

406 Pages·2015·16.37 MB·English

AP Physics 1 Essentials
*
An APlusPhysics Guide
2nd Edition
Dan Fullerton
Physics Teacher
Irondequoit High School
Adjunct Professor
Microelectronic Engineering
Rochester Institute of Technology
*AP and Advanced Placement Program are registered trademarks of
the College Board, which does not sponsor or endorse this product.
Dedication
This book is dedicated to the many students and educators
who have supported the APlusPhysics site and series of
instructional resources. Without your support and encouragement,
this project would have dissipated years ago. Thank you.
Credits
Thanks To:
Peter Geschke, Mike Powlin, Tom Schulte, Dolores Gende, Joe Kunz, Laurie Peslak,
Mike Dalessandro, Rob Spencer, Karen Finter, Scott Mathieson, Joanne Schwager,
Dan Burns, Amy Pezzoni, Bob Enck, Paul Sedita
Silly Beagle Productions
656 Maris Run
Webster, NY 14580
Internet: www.SillyBeagle.com
E-Mail: [email protected]
No part of this book may be reproduced in whole or in part by any mechanical, photo-
graphic, or electronic process, nor may it be stored in a retrieval system, transmitted,
shared, or otherwise copied for public or private use, without the prior written permission
of the author.
© Copyright 2014 Dan Fullerton
[email protected]
Cover Design:
Interior Illustrations by Dan Fullerton, Jupiterimages and NASA unless otherwise noted
All images and illustrations ©2014 Jupiterimages Corporation and Dan Fullerton
Edited by Joe Kunz
AP, AP Physics 1, Advanced Placement Program, and College Board are registered trademarks of
the College Entrance Examination Board, which was not involved in the production of, and does
not endorse, this product.
Sales and Ordering Information
http://www.aplusphysics.com/ap1
[email protected]
Volume discounts available.
E-book editions available.
Printed in the United States of America
ISBN: 978-0-9907243-0-8
1 2 3 4 5 6 7 8 9 0 9 8
elcome to AP Physics 1 Essentials - an APlusPhysics Guide.
W
From mechanics to momentum and sound to circuits,
this book is your essential physics resource for
use as a standalone guide, a companion to classroom
text, or as a review book for your AP Physics 1 course.
What sets this book apart from other review books?
1. It reviews the essential concepts and understand-
ings required for success in AP Physics 1, and is written
specifically to prepare students for optimal performance
on the AP Physics 1 Exam.
2. It includes more than 500 sample questions with full
solutions, integrated into the chapters immediately
following the material being covered, so you can test
your understanding. You’ll also find tons of AP-style
problems at the end of the book.
3. It is supplemented by the free APlusPhysics.com web-
site, which includes:
a. Videos and tutorials on key physics concepts
b. Interactive practice quizzes
c. Discussion and homework help forums supported by
the author and fellow readers
d. Student blogs to share challenges, successes, hints and
tricks
e. Projects and activities designed to improve your un-
derstanding of essential physics concepts in a fun and
engaging manner
f. Latest and greatest physics news
Just remember, physics is fun! It’s an exciting course, and with a little
preparation and this book, you can transform your quest for essential
physics comprehension from a stressful chore into an enjoyable and, yes,
FUN, opportunity for success.
How to Use This Book
This book is arranged by topic, with sample problems and solutions inte-
grated right in the text. Actively explore each chapter. Cover up the in-
text solutions with an index card, get out a pencil, and try to solve the
sample problems yourself as you go, before looking at the answer. If
you’re stuck, don’t stress! Post your problem on the APlusPhysics website
(http://aplusphysics.com) and get help from other students, teachers, and
subject matter experts (including the author of this book!). Once you feel
confident with the subject matter, test yourself and see how you perform. Re-
view areas of difficulty, then try again and watch your understanding improve!
* There are a number of topics presented in this book which are typically
included in an introductory physics course but are not specifically tested on
the AP Physics 1 Exam. These topics are marked with an asterisk to allow
those focused solely on preparing for the AP Physics 1 Exam to bypass them
in favor of topics that they know will be tested.

Table of Contents
Chapter 1: Introduction 1
What is Physics? 2
Matter, Systems, and Mass 2
Energy 3
Mass – Energy Equivalence 4
Scope of AP Physics 1 4
Chapter 2: Math Review 7
Significant Figures 8
Scientific Notation 9
Metric System 10
Accuracy and Precision 13
Algebra and Trigonometry 13
Vectors and Scalars 15
Components of Vectors 16
The Equilibrant Vector 21
Chapter 3: Kinematics 23
Position, Distance, and Displacement 25
Speed and Velocity 27
Acceleration 31
Particle Diagrams 33
Position-Time (x-t) Graphs 34
Velocity-Time (v-t) Graphs 36
Graph Transformations 37
Acceleration-Time (a-t) Graphs 40
Kinematic Equations 43
Free Fall 48
Projectile Motion 56
Angled Projectiles 59
Relative Velocity 64
Center of Mass 68
Test Your Understanding 70
Chapter 4: Dynamics 71
Newton’s 1st Law of Motion 72
Free Body Diagrams 74
Newton’s 2nd Law of Motion 76
Newton’s 3rd Law 84
Friction 86
Air Resistance 93
Elevators 94
Ramps and Inclines 95
Atwood Machines 100
Test Your Understanding 104
Chapter 5: Work, Power & Energy 105
Work 106
Power 112
Energy 116
Gravitational Potential Energy 117
Springs and Hooke’s Law 120
Work-Energy Theorem 125
Conservation of Energy 128
Sources of Energy on Earth 137
Test Your Understanding 138
Chapter 6: Linear Momentum 139
Defining Momentum 140
Impulse 142
Impulse-Momentum Theorem 143
Non-Constant Forces 146
Conservation of Linear Momentum 148
Types of Collisions 157
Collisions in 2 Dimensions 160
Test Your Understanding 162
Chapter 7: Circular Motion & Rotation 163
Uniform Circular Motion 164
Circular Speed 167
Centripetal Force 168
Frequency and Period 171
Vertical Circular Motion 172
Rotational Kinematics 176
Torque 185
Moment of Inertia 188
Newton’s 2nd Law for Rotation 190
Angular Momentum 193
Rotational Kinetic Energy 196
Test Your Understanding 200
Chapter 8: Gravity 201
Universal Gravitation 202
Gravitational Fields 205
Gravitational Potential Energy 209
Orbits 211
Kepler’s Laws of Planetary Motion* 215
Test Your Understanding 220
Chapter 9: Oscillations 221
Simple Harmonic Motion 222
Horizontal Spring-Block Oscillators 224
Spring Combinations* 228
Vertical Spring-Block Oscillators 229
Ideal Pendulums 231
Test Your Understanding 235
Chapter 10: Mechanical Waves 237
Wave Characteristics 238
The Wave Equation 244
Sound Waves 247
Interference 250
Beats 253
Standing Waves 255
Standing Waves in Instruments 258
Doppler Effect 261
Test Your Understanding 264
Chapter 11: Electrostatics 265
Electric Charges 266
The Standard Model 268
Conductors and Insulators 271
Charging by Conduction* 272
Charging by Induction* 273
Coulomb’s Law 275
Electric Fields* 278
Electric Potential Difference* 284
Parallel Plates* 286
Capacitors* 288
Equipotential Lines* 290
Test Your Understanding 290
Chapter 12: Current Electricity 291
Electric Current 292
Resistance 294
Ohm’s Law 296
Electrical Circuits 299
Energy & Power 300
Voltmeters 302
Ammeters 302
Series Circuits 304
Parallel Circuits 310
Combination Series-Parallel Circuits 317
Test Your Understanding 320
Appendix A: AP-Style Problems 321
Kinematics 321
Dynamics 328
Work, Power & Energy 341
Linear Momentum 347
Circular Motion & Rotation 354
Gravity 366
Oscillations 372
Mechanical Waves 381
Electricity 387
Index 395
Chapter 1: Introduction
“There is a theory which states that if ever anybody
discovers exactly what the Universe is for and why
it is here, it will instantly disappear and be replaced
by something even more bizarre and inexplicable.
There is another theory which states that this has
already happened.”
— Douglas Adams
Objectives
Explore the scope of AP Physics 1 and review prerequisite skills for success.
1. Recognize the questions of physics.
2. List several disciplines within the study of physics.
3. Describe the key topics covered in AP Physics 1.
4. Define matter, mass, work and energy.
5. Explain how systems are comprised of constituent substructures.
6. Recognize when a system may be treated as an object.
Chapter 1: Introduction 1
What is Physics?
Physics is many things to many different people. If you look up physics in the
dictionary, you’ll probably learn physics has to do with matter, energy, and
their interactions. But what does that really mean? What is matter? What
is energy? How do they interact? And most importantly, why do we care?
Physics, in many ways, is the answer to the favorite question of most 2-year-
olds: “Why?” What comes after the why really doesn’t matter. If it’s a “why”
question, chances are it’s answered by physics: Why is the sky blue? Why
does the wind blow? Why do we fall down? Why does my teacher smell
funny? Why do airplanes fly? Why do the stars shine? Why do I have to
eat my vegetables? The answer to all these questions, and many more, ul-
timately reside in the realm of physics.
Matter, Systems, and Mass
If physics is the study of matter, then we probably ought to define matter.
Matter, in scientific terms, is anything that has mass and takes up space.
In short, then, matter is anything you can touch – from objects smaller than
electrons to stars hundreds of times larger than the sun. From this per-
spective, physics is the mother of all science. From astronomy to zoology,
all other branches of science are subsets of physics, or specializations inside
the larger discipline of physics.
In physics, you’ll often times talk about systems as collections of smaller
constituent substructures such as atoms and molecules. The properties and
interactions of these substructures determine the properties of the system.
In many cases, when the properties of the constituent substructures are
not important in understanding the behavior of the system as a whole, the
system is referred to as an object. For example, a baseball is comprised of
many atoms and molecules which determine its properties. For the purpose
of analyzing the path of a thrown ball in the air, however, the makeup of its
constituent substructures is not important; therefore, we treat the ball as a
single object.
So then, what is mass? Mass is, in simple terms, the amount of “stuff” an
object is made up of. But of course, there’s more to the story. Mass is split
into two types: inertial mass and gravitational mass. Inertial mass is an
object’s resistance to being accelerated by a force. More massive objects
accelerate less than smaller objects given an identical force. Gravitational
mass, on the other hand, relates to the amount of gravitational force expe-
rienced by an object. Objects with larger gravitational mass experience a
larger gravitational force.
Confusing? Don’t worry! As it turns out, in all practicality, inertial mass and
gravitational mass have always been equal for any object measured, even if
it’s not immediately obvious why this is the case (although with an advanced
study of Einstein’s Theory of General Relativity you can predict this outcome).
2 Chapter 1: Introduction