Tài liệu Sat ii physics (gary graff).6277

About The Thomson Corporation and Peterson’s With revenues approaching US$6 billion, The Thomson Corporation (www.thomson.com) is a leading global provider of integrated information solutions for business, education, and professional customers. Its Learning businesses and brands (www.thomsonlearning.com) serve the needs of individuals, learning institutions, and corporations with products and services for both traditional and distributed learning. Peterson’s, part of The Thomson Corporation, is one of the nation’s most respected providers of lifelong learning online resources, software, reference guides, and books. The Education SupersiteSM at www.petersons.com—the Internet’s most heavily traveled education resource—has searchable databases and interactive tools for contacting U.S.-accredited institutions and programs. In addition, Peterson’s serves more than 105 million education consumers annually. Artwork by Timothy J. Finley Editorial Development: Sonya Kapoor Turner Special thanks to my wife, Faye, and Mrs. Cathy Walton. For more information, contact Peterson’s, 2000 Lenox Drive, Lawrenceville, NJ 08648; 800-338-3282; or find us on the World Wide Web at www.petersons.com/about. COPYRIGHT © 2002 Peterson’s, a division of Thomson Learning, Inc. Previous edition © 2001. Thomson LearningTM is a trademark used herein under license. ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced or used in any form or by any means—graphic, electronic, or mechanical, including photocopying, recording, taping, Web distribution, or information storage and retrieval systems—without the prior written permission of the publisher. For permission to use material from this text or product, contact us by Phone: 800-730-2214 Fax: 800-730-2215 Web: www.thomsonrights.com ISBN 0-7689-0960-0 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 04 03 02 CONTENTS Red Alert .....................................................1 About the Book .......................................................... 1 About the Physics Test ............................................... 2 Scoring .............................................................................. 3 Taking the Test .................................................................. 3 SAT II Physics Study Plans ......................................... 4 Preliminary Preparations .................................................. 5 The 18-week Plan .............................................................. 6 The 9-Week Plan ............................................................... 8 Panic Plan .......................................................................... 9 Key Formulas and Equations ................................... 11 Units and Conversions ............................................. 12 Diagnostic Test ...........................................13 Answers and Explanations ...................................... 31 Chapter 1: Preliminary Concepts .................45 Simple Equations and Algebra ................................. 47 Graphs ...................................................................... 48 Right Triangles ......................................................... 52 Units and Conversions ............................................. 56 Scalars and Vectors ................................................... 57 Chapter Summary .................................................... 67 Chapter 2: Mechanics .................................69 Statics ...................................................................... 71 CONTENTS Torques ..................................................................... 77 Kinematics ............................................................... 80 Motion in Two Dimensions...................................... 87 Newton’s Laws of Motion ........................................ 90 Work and Energy ..................................................... 96 Momentum............................................................. 100 Circular and Rotary ................................................ 103 Chapter Summary .................................................. 109 Chapter 3: Waves ....................................113 Wave Properties ..................................................... 115 Chapter Summary .................................................. 135 Chapter 4: Heat and Thermodynamics ......................................137 Temperature ........................................................... 139 Thermal Properties of Matter ................................ 140 Thermodynamics ................................................... 149 Chapter Summary ................................................. 160 Chapter 5: Electricity and Electromagnetism .....................................161 Electrostatics .......................................................... 163 Electric Fields ......................................................... 166 Electric Circuits ...................................................... 168 Magnets and Magnetic Fields ................................ 179 Chapter Summary .................................................. 191 CONTENTS Chapter 6: Modern Physics .......................193 Particulate Theory of Light .................................... 195 Photoelectric Effect ................................................ 198 Relativity ................................................................. 201 Chapter Summary .................................................. 211 Chapter 7: The Atom.................................213 The Atom ................................................................ 215 Radioactivity ........................................................... 224 Particles .................................................................. 232 Chapter Summary .................................................. 234 Practice Test 1 ..........................................237 Practice Test 2 ..........................................271 Practice Test 3 ..........................................305 Practice Test 4 ..........................................337 RED ALERT ABOUT THE BOOK Now that you have decided to tackle the SAT II Physics Test, you need to develop a plan to maximize your chances of achieving a high score. The reason you want a high score is simple. The higher your score, the better you look to the admissions officers at the college of your choice. The SAT II Physics Test is designed to measure the knowledge and achievement of high school students who have completed a college preparatory physics class. This book will help you review for the SAT II Physics Test. If you have not taken a Physics class yet, it may be advisable to wait until after you complete one before you progress further. This book is arranged in several sections, beginning with a diagnostic test. The purpose of this test is to identify your strengths and weaknesses. It will also help to familiarize you with the testing method used by the College Board. Do not skip the diagnostic test! Find a quiet, comfortable spot, turn off the TV, computer, and music, and try to take the entire diagnostic test within the time allotted. If you run out of time, mark on your answer sheet where you ran out of time. Then keep going until you complete the test. After finishing the test, you deserve a break, so take one. But be sure to come back after no more than 15 minutes and check your answers. Then go back, reread the questions you missed, and try to figure out what went wrong. Did you jump to a conclusion, misread the question, stop at the first correct answer (sometimes there are multiple correct answers to one question), or just not know the material? None of these reasons is cause for serious concern right now, because every reason mentioned can be overcome. In fact, as you work through this book, each of these will be addressed. Once the diagnostic test is done it’s time to settle down to your preparation for the real SAT II Physics Test. Move on to the Physics review and study each section as if you had to learn the material all over again. Those sections you know well will go by smoothly and help you to build confidence, while your review of unfamiliar terms and concepts will allow you to learn it quickly and effectively. Peterson’s: www.petersons.com RED 1 ALERT RED ALERT When you have finished your review, take the practice tests. Once again, you should try to set up a test-like situation. Make sure all the electronic toys are out of the way (besides, the College Board doesn’t allow them), time yourself, and do your best. After you check each test, read the explanations for those questions you missed, and for additional reinforcement, reread the Review Section that covers the material in the question. ABOUT THE PHYSICS TEST The SAT II Physics Test is a 75-question multiple-choice test. The test covers the following topics: • • • • • • Mechanics Heat/Kinetic Theory/Thermodynamics Waves Electricity and Magnetism Modern Physics Miscellaneous Topics (may include measurement, math, and history) Nearly 40 percent of the SAT II Physics Test will test your knowledge of Mechanics. Electricity and Magnetism also make up a significant proportion of the material, accounting for about 25 percent of the questions. Approximately 20 percent of the questions deal with waves, and the remaining 15 percent covers the other topics listed above. Because the material covered in high school physics courses can vary widely, you will probably find some questions on the test that cover topics with which you are unfamiliar. This may be impossible to avoid entirely; however, solid preparation and review of the concepts and information covered in this book will go a long way to helping you navigate unfamiliar territory. The testing procedures for the SAT II Physics Test are similar to those you already know from your high school classroom. A few questions will be simple recall; about half of the questions will require you to be able to apply a physical concept for a given situation; and the more difficult questions will require that you be able to apply multiple concepts to multiple relationships. In addition to a college preparatory physics course, you will also need a solid working knowledge of algebra and trigonometry, as well as laboratory experience. Familiarity with the metric system is critical. You ar e not per mitted to use a calculator dur ing the test. are permitted during The calculations focus on simple arithmetic and will not require a calculator. RED 2 ALERT Peterson’s SAT II Success: Physics RED ALERT SCORING Your score on the SAT II Physics Test will be reported on a scale of 200–800. Each question you answer correctly counts as one point. Each incorrect answer counts as 1 4 point against you. Unanswered questions do not count for or against you. Clearly, the more incorrect answers you can eliminate from a set of choices, the better your chances of finding or guessing the correct answer. TAKING THE TEST You will be given one hour (60 minutes) to complete seventy-five questions. Because of the limited amount of time you have for each question, it is vital that you adopt a test-taking strategy and stick to it. There are several things that you can do to give yourself the best possible chance to score well on the test. Set up a study program for yourself and faithfully follow it. Do not skip any part(s) of the program. 1. When you take the diagnostic and practice tests, make sure to familiarize yourself thoroughly with the test directions, as they are patterned after the actual directions on the SAT II Physics Test you will be taking. Becoming familiar with the directions saves you time in re-reading them on test day. 2. Quickly read the entire test question by question. Answer immediately the questions you know or can do as you read through the test the first time; skip those questions you can’t answer right away. 3. Once you’ve gone through the entire test, go back to the beginning and work on the questions you skipped. Look for answers to eliminate. The more answers you can eliminate, the better your chances to recognize or guess the correct answer. 4. If you finish the test before time is up, go back and look over your answers. Only change an answer if you are absolutely sure you have the incorrect answer selected. 5. Get a good rest the night before the test. A primary reason for poor test performance is lack of sleep. Peterson’s: www.petersons.com RED 3 ALERT RED ALERT SAT II PHYSICS STUDY PLANS You already know the importance of a study plan when preparing for this test. Needless to say, the amount of time you have before you’re due to take the test has a lot to do with which of the following plans you’ll select for your exam preparation. Those of you who are not taking the SAT II Physics Test in the near future should follow our leisurely 18-week plan. This plan is favored because it gives you plenty of time to thoroughly prepare, review all required concepts, and restudy the material you find challenging. The next option is the 9-week plan, which calls for a more concentrated effort on your part. You will have to pay more attention to your diagnostic and practice test results in this plan, as those questions you miss become indicators for the material to which you should pay extra attention. Finally, the last method is the Panic Plan. This plan is for you if you’ve got hardly any time to prepare but still want to do your best, like when you find out your college of choice wants to see your SAT II Physics Test score and the next test administration is in just a few weeks! Using this plan you will spend as much time as you have available preparing for the SAT II Physics Test by using this book to line you up for the test. RED 4 ALERT Peterson’s SAT II Success: Physics RED ALERT PRELIMINARY PREPARATIONS Browse through the book. Look at the chapter summaries. Take the Diagnostic Test. Follow the instructions for taking the test and then check your answers. After you have taken the test and graded it, be sure to read all the explanations for the answers. Pay particular attention to the explanations for the questions you missed. Try to identify the reasons why you answered a question incorrectly. Was it carelessness on your part? You would be surprised at the number of students who miss a question they knew by inadvertently marking the wrong choice. Perhaps you misread the question, or maybe you were hurrying too much. Look through the answers and explanations for the questions you missed. Be sure you understand why the correct answer is correct. Write down the numbers of the questions you missed or would like to understand a little better. They are your benchmark questions. If you miss a lot of the questions about magnetism or thermodynamics, for example, this tells you where to concentrate your efforts. Identifying these weak areas is especially important if you are following the Panic Plan and will be helpful no matter how long you have to prepare. Sometimes students say the test questions are tricky, but the students who know the material are difficult to fool and quickly eliminate the “tricky” answers. This is not to say that they don’t have to think about what they are doing. Some of the questions are truly challenging and will require your best effort, so prepare yourself well. Start each chapter by reading the summary at the end, which lists everything in the chapter. As you read through a chapter, work out the problems on your own when you come to them. When you reach the werful end of a chapter, read the summary again. Repetition is a po pow learning tool. Peterson’s: www.petersons.com RED 5 ALERT RED ALERT THE 18-WEEK PLAN Week 1 Diagnostic Test Review the answers to the Diagnostic Test. Review Chapter 1: Preliminary Concepts Week 2 Chapter 2 2:: Mechanics Statics Kinematics Dynamics Week 3 Chapter 2 2:: Mechanics Work and Energy Momentum Circular and Rotary Motion Week 4 Chapter 3: Waves Wave Properties Reflection Refraction Week 5 Chapter 3 3:: Waves Polarization of Light Interference Diffraction Week 6 Chapter 4 mod ynamics 4:: Heat and Ther Thermod modynamics Thermal Properties of Matter Kinetic Molecular Theory Gases Week 7 Chapter 4 mod ynamics 4:: Heat and Ther Thermod modynamics Laws of Thermodynamics Heat Engines Calorimetry Week 8 Chapter 5 5:: Electricity and Electromagnetism Coulombs Law Electric Fields and Potential DC Circuits Week 9 Chapter 5 5:: Electricity and Electromagnetism Magnets and Magnetic Fields RED 6 ALERT Peterson’s SAT II Success: Physics RED ALERT Week 10 Chapter 6 6:: Modern Physics Quantum Mechanics Work Function Week 11 Chapter 6 6:: Modern Physics Relativity Heisenberg Compton deBroglia Week 12 Chapter 7 7:: The Atom The Nucleus Atomic Spectra Bohr’s Atom Week 13 Chapter 7 7:: The Atom Nuclear Reactions, Equations, and Radiation Fission and Fusion Binding Energy and Mass Defect Week 14 Pr actice Test 1 and Pr actice Test 2 Practice Practice Review Answers and Explanations Reread all the chapter summaries Week 15 Review the material from the questions you missed on Practice Test 1 and Practice Test 2 Reread the chapter summaries Week 16 Pr actice Test 3 and Pr actice Test 4 Practice Practice Review Answers and Explanations Reread all the chapter summaries Week 17 Review the material from the questions you missed on Practice Test 3 and Practice Test 4 Reread the chapter summaries Week 18 Start the week by reading all of the chapter summaries. Go over all of the test questions you missed on the Diagnostic Test and the four practice tests. Review the material you are not sure you have mastered! Think positive. You are ready! Peterson’s: www.petersons.com RED 7 ALERT RED ALERT THE 9-WEEK PLAN Week 1 Diagnostic Test Chapter 1 eliminar y Concepts 1:: Pr Preliminar eliminary Week 2 Chapter 2 2:: Mechanics Week 3 Chapter 3 3:: Waves Week 4 mod ynamics Chapter 4 4:: Heat and Ther Thermod modynamics Week 5 Chapter 5 5:: Electricity and Electromagnetism Week 6 Chapter 6 6:: Modern Physics Week 7 Chapter 7 7:: The Atom Week 8 Pr actice Tests 1 and 2 Practice Review the answers to the questions you missed Week 9 Pr actice Tests 3 and 4 Practice Review the answers to the questions you missed. Reread the chapter summaries, paying particular attention to any material you missed previously RED 8 ALERT Peterson’s SAT II Success: Physics RED ALERT PANIC PLAN This last plan is for the group of students (and I hope it is small) who for whatever reason don’t have much time to prepare for the SAT II Physics Test. Perhaps you have just completed a physics class and you don’t think you need to spend much time in preparation, or maybe you have just decided to take the test. Only you know how much study time you have and how much energy you are willing to devote to preparation. Try to use both your time and energy wisely. The list below will help you to prepare for the test in whatever time you have available. By all means try to do everything on the list. If that is not a possibility, the most important items are first. Do them! In fact do as much as you can. • Read the chapter summaries, which will help you renew your basic physics knowledge. • Take the Diagnostic Test, and review the questions you miss. This gives you an idea of your needs. • Take Practice Test 1, and go over any questions you miss. • Take Practice Test 2, and go over the questions you miss. • Take Practice Test 3, and go over the questions you miss. • Take Practice Test 4, and go over the questions you miss. • Reread the chapter summaries Good luck! Peterson’s: www.petersons.com RED 9 ALERT KEY FORMULAS AND EQUATIONS ∆y Slope = ∆x 2 2 r =y +x nλ = d sinq 1 S = Vo t + at 2 2 PV = n r t P1 V1 = P2 V2 2 S= y sin q = r 1 2 gt 2 V1 V2 = T1 T2 F = ma P1 P2 = T1 T2 Wt = mg x cos q = r Work = F • S • cos q PE = mgh tan q = y x KE= l/2 mv Power = ∑F=0 ∑ Fx = 0 ∑ Fy = 0 P = mv ∑ Fz = 0 Ft = m∆V Τ = F≥ Fc = ∑Τ=0 ∑ +Τ = ∑ −Τ Speed (U) distance d = time t V= V f + V0 2 ∆V = Vf – V0 ∆t = t f –to a= a= ∆V ∆t V f − V0 t f − t0 Vf = V0 + at Vf2 = Vo2 +2as Peterson’s: www.petersons.com ( P1 )(V1 ) ( P2 )(V2 ) = T1 T2 2 ∆Q = ∆U + ∆W work time Q = cm∆T F=K (q1 )(q2 ) r2 F = EQ mV 2 r V = IR Rt = R1 + R2 + R3 + R… (m )(m ) F =G 1 2 2 r θradians = S V= t 1 1 1 1 = + + Rt R1 R2 R 3 arclength s = radius r P = VI F = B⊥ IL stan = qr F = B⊥ qV Vtan = Wr EMF = BLV atan = αr Vs N s = Vp N p V= λf f = Relativistic Factor 1 Τ E = hf φ = hf ∆ E = E2 –E1 hi q = h0 p 1 1 1 = + f p q n1sin q1 = n2 sin q2 (Snell’s Law) 11   1   v 2  1− (c)        E = mc2 Activity = T1/2 = ∆N ∆t .693 λ ∆N = λN o ∆t UNITS AND CONVERSIONS SI Units length meter m mass kilogram kg time second s electric current ampere A temperature Kelvin K Metric Prefixes T tera 1 × 10 G giga 1 × 109 10 9 M mega 1 × 106 10 6 hK hectokilo 1 × 105 10 5 ma myria 1 × 104 10 4 K kilo 1 × 103 10 3 h hecto 1 × 102 10 2 d deka 1 × 101 10 1 Basic Unit 12 10 12 1 meter – 1 gram – 1 liter d c m deci centi milli 1 × 10–1 –2 1 × 10 1 × 10–3 10 –1 –2 10 10 –3 dm decimilli 1 × 10–4 10 –4 cm centimilli 1 × 10–5 10 –5 u micro 1 × 10–6 10 –6 n nano 1 × 10–9 10 –9 p pico 1 × 10–12 10 –12 12 Peterson’s SAT II Success: Physics Diagnostic Test PHYSICS TEST