STEP 1 Set Up Your Study Program
2 What You Need to Know About the AP Physics 2 Exam
IN THIS CHAPTER
Summary: Learn what topics are tested, how the test is scored, and basic test-taking information.
Most colleges will award credit for a score of 4 or 5, many for a 3.
Multiple-choice questions account for half of your final score.
There is no penalty for guessing on the multiple-choice questions. You should answer every question.
Free-response questions account for half of your final score. Answering questions correctly, or even partially correct, earns points. There are no penalties for wrong answers. Therefore, you should fill in every part of the free-response as best as you can and never leave anything blank.
Your composite score on the two test sections is converted to a score on the 1-to-5 scale.
You have to know your physics to do well on the exam. You can’t “sweet talk” your way to a good score.
The test focuses on deep conceptual understanding and the ability of students to explain things using the language of physics.
Some Frequently Asked Questions About the AP Physics 2 Exam
Why Should I Take the AP Physics Exam?
Many of you take the AP Physics exam because you are seeking college credit. The majority of colleges and universities will award you some sort of credit for scoring a 4 or a 5. Many schools will accept a 3 on the exam. This means you are one or two courses closer to graduation before you even start college!
Therefore, one compelling reason to take the AP exam is economics. How much does a college course cost, even at a relatively inexpensive school? You’re talking several thousand dollars. If you can save those thousands of dollars by paying less than a hundred dollars now, why not do so?
Even if you do not score high enough to earn college credit, the fact that you elected to enroll in AP courses tells admission committees that you are a high achiever and serious about your education.
You’ll hear a whole lot of misinformation about AP credit policies. Don’t believe anything a friend (or even an adult) tells you; instead, find out for yourself. A good way to learn about the AP credit policy of the school you’re interested in is to look it up on the College Board’s official Web site, at https://apstudents.collegeboard.org/getting-credit-placement/search-policies. Even better, contact the registrar’s office or the physics department chairman at the college directly.
What’s the Deal with All the Different AP Physics Courses (Physics 1, Physics 2, and Physics C)?
There are four AP Physics courses you can take, Physics 1, Physics 2, Physics C—Mechanics, and Physics C—Electricity and Magnetism, and they are different in the depth of the material and mathematical modeling. Here’s the rundown.
Physics 1 and 2
As survey courses, Physics 1 and 2 cover a broad range of topics. These courses are algebra-based—no calculus is necessary. In fact, the most difficult math you will encounter will be algebraic equations and basic trigonometry, which is probably something you did by the tenth grade.
The Physics 1 and 2 courses are ideal for all college-bound high school students. For those who intend to major in math or the heavy-duty sciences, Physics 1 and 2 serve as perfect introductions to college-level work. For those who want nothing to do with physics after high school, Physics 1 and 2 are terrific terminal courses—you get exposure to many facets of physics at a rigorous yet understandable level.
Most important, for those who aren’t sure in which direction their college careers may head, the Physics 1 and 2 courses can help you decide: “Do I like this stuff enough to keep studying it or not?”
These courses are ONLY for those who have already taken a solid introductory physics course and are considering a career in math or science. Some schools teach Physics C as a follow-up to Physics 1 and 2, but as long as you’ve had a rigorous introduction to the subject, that introduction does not have to be at the AP level.
Physics C is two separate courses: (1) Newtonian Mechanics, and (2) Electricity and Magnetism. Of course, the Physics 1 and 2 courses cover these topics as well. However, the C courses go into greater depth and detail. The problems are more involved, and they demand a higher level of conceptual understanding. You can take either or both 90-minute Physics C exams.
The C courses require some calculus. Although much of the material can be handled without it, you should be taking a good calculus course concurrently.
There Are So Many Different AP Physics Exams. Which One Should I Take?
This is a no-brainer. Take the exam that your high school class is preparing you for! If you are taking AP Physics 2 at your school right now, sign up for the AP Physics 2 exam.
Is One Exam Better Than the Other? Should I Take Them Both?
I strongly recommend taking only one exam—the one your high school AP course prepared you for. Physics C is not considered “better” than Physics 1 and 2 in the eyes of colleges and scholarship committees. They are different courses with different intended audiences. It is far better to do well on the one exam you prepared for than to do poorly on both exams.
What Is the Format of the Exam?
Table 1.1 summarizes the format of the AP Physics 2 exam, which is identical to the AP Physics 1 exam.
Table 1.1 AP Physics 2 Exam
You are probably asking yourself, what does that all mean?
• In the multiple-choice section, there will be a total of 50 questions; the first 45 will have only one correct answer. The last 5 will have two correct answers. They will be clearly marked so you won’t have to guess which is which. I know you are asking yourself: “Can I get half credit if I get only one right on these last five?” Unfortunately not. You have to get both correct to receive credit.
• There will be one laboratory free-response question where you will have to design a laboratory experiment and interpret laboratory data to solve a problem to determine or discover a pattern of behavior.
• The quantitative/qualitative question is a problem you will have to solve mathematically in symbol form and be able to explain in writing how you went about solving the problem.
• The short-answer questions can require a verbal, algebraic, graphical, or numerical answer.
• Included in one of the short-answer questions will be a statement like: “In a clear, coherent paragraph-length response, explain . . .” followed by a large expanse of open paper. When students see this, their brains tend to go into “English class mode” and they begin writing, and writing, and writing. This is a physics exam. If you need a lot of words, it usually means that your understanding of the answer is not very good and your score will be lower. Your paragraph should be concise (short and to the point) and coherent (easy to understand in only one quick reading). What the test graders want here is called technical writing: explaining something in an economy of words. If you can clearly and completely answer the question in three sentences, please do so!
Who Writes the AP Physics Exam?
Development of each AP exam is a multiyear effort that involves many education and testing professionals and students. At the heart of the effort is the AP Physics Development Committee, a group of college and high-school physics teachers who are typically asked to serve for three years. The committee and other physics teachers create a large pool of multiple-choice questions. With the help of the testing experts at Educational Testing Service (ETS), these questions are then pre-tested with college students for accuracy, appropriateness, clarity, and assurance that there is only one possible answer. The results of this pre-testing allow each question to be categorized by degree of difficulty. After several more months of development and refinement, Section I of the exam is ready to be administered.
The free-response questions that make up Section II go through a similar process of creation, modification, pre-testing, and final refinement so that the questions cover the necessary areas of material and are at an appropriate level of difficulty and clarity. The committee also makes a great effort to construct a free-response exam that will allow for clear and equitable grading by the AP readers.
At the conclusion of each AP reading and scoring of exams, the exam itself and the results are thoroughly evaluated by the committee and by ETS. In this way, the College Board can use the results to make suggestions for course development in high schools and to plan future exams.
What Topics Appear on the Exam?
The College Board published the Course and Exam Description, which describes AP Physics 2 in great detail. The bottom line is that there are seven major topic areas for AP Physics 2:
• Fluids (this includes both liquids and gases)
• Electric Force, Field, and Potential
• Electric Circuits
• Magnetism and Electromagnetic Induction
• Physical and Geometric Optics
• Quantum, Atomic, and Nuclear Physics
Can I Use a Calculator? Will There Be an Equation Sheet?
Yes! You can use a calculator and are given an equation and constant sheet to use on the entire exam. But . . . don’t plan on using them very much. There are not that many numerical problem-solving questions on the exam. Roughly two-thirds of the questions on the exam won’t have any numbers at all. Many of the problems with numbers will be solved using semi-quantitative reasoning where you need to know what the equation means, but won’t be doing any calculator work. For example:
A scientist has a sample of gas at atmospheric pressure and a temperature of 300 K. The gas is in a sealed container with a movable piston that has an original volume of 30 cm3. Wanting to study the behavior of the gas, the scientist pushes the piston until the gas has a volume of 15 cm3 and measures the pressure to be 2 atmospheres. What new temperature will the gas have?
Let’s find the answer using semi-quantitative reasoning:
• I have a gas that’s changing pressure and volume, so let’s start with the universal gas law: PV = nRT.
• The gas is in a sealed container so the number of moles will be constant and universal gas constant R is a constant. That leaves us with this relationship: (pressure times volume is proportional to the temperature).
• Pressure is doubled and volume is cut in half, so the temperature remains unchanged!
You can see that trying to solve this problem with a calculator just makes things harder. The bottom line on calculators: You shouldn’t use your calculator much on the exam. (Every year my students tell me that they only used their calculator on about two to five problems on the entire exam!) Try to use semi-quantitative reasoning first because it’s faster and easier.
Concerning the equation sheet: First of all, memorize your equations! I know that is not what you wanted to hear, but if you waste time hunting for an equation during the exam you probably won’t do very well. I’ll say it again: Memorize your equations! That being said, if your teacher does not give you an official AP Physics 2 equation table to use in class, print one out for yourself from https://apstudents.collegeboard.org/courses/ap-physics-2-algebra-based/assessment. Study it. Make sure you know what is and what is not on it. Not every equation you might need is on the equation table. As you study physics this year, highlight the equations you learn and write notes next to them explaining what they mean and when they are useful. Add any equations that may be missing. I’m telling you to do all these things so that you will memorize the equations and become intimately familiar with the formulas you will be using. That way if your brain goes blank during the exam, you won’t waste any time finding what you need.
How Is the Multiple-Choice Section Scored?
The multiple-choice section counts for half of your total score. There is no partial credit on the five multiple-correct questions. There are two correct responses on these and you have to choose them both to get credit.
Should I Guess If I Don’t Know the Answer?
Yes. Don’t leave anything blank. There is no guessing penalty. Try your best to eliminate at least one response that can’t be correct before you guess. This “educated guessing” will improve your score.
How Is the Free-Response Section Graded?
Every June, a group of physics teachers gather for a week to assign grades to your hard work. Each of these “readers” spends a day or so getting trained on one question—and one question only. Because each reader becomes an expert on that question, and because each exam book is anonymous, this process provides a very consistent and unbiased scoring of that question.
During a typical day of grading, a random sample of each reader’s scores is selected and cross-checked by other experienced “Table Leaders” to ensure that the consistency is maintained throughout the day and the week. Each reader’s scores on a given question are also statistically analyzed, to make sure they are not giving scores that are significantly higher or lower than the mean scores given by other readers of that question. All measures are taken to maintain consistency and fairness for your benefit.
Special note: You want to make the grading of your free-response answers as easy as possible for the reader. Readers do everything in their power to be consistent and fair. But, if your handwriting is poor and you don’t write in a coherent, logical, and concise manner, it is hard for you to receive credit. I always tell my students that the readers are very nice people who want you to do well. But they can’t grade what they can’t read. The readers grade many thousands of papers. They don’t have the time to hunt through a maze of your gibberish. Make the reader your friend. Provide a clean, easy-to-read, and orderly response.
Will My Exam Remain Anonymous?
Absolutely. Even if your high-school teacher happens to randomly read your booklet, there is virtually no way he or she will know it is you. To the reader, each student is a number, and to the computer, each student is a bar code.
What About That Permission Box on the Back?
The College Board uses some exams to help train high-school teachers so that they can help the next generation of physics students to avoid common mistakes. If you check this box, you simply give permission to use your exam in this way. Even if you give permission, your anonymity is still maintained.
How Is My Final Grade Determined and What Does It Mean?
As I said, each section counts for 50% of the exam. The total composite score is thus a weighted sum of the multiple-choice and the free-response sections. In the end, when all of the numbers have been crunched, the Chief Faculty Consultant converts the range of composite scores to the 5-point scale of the AP grades. This conversion is not a true curve—it’s not that there’s some target percentage of 5s to give out. This means you’re not competing against other test takers. Rather, the 5-point scale is adjusted each year to reflect the same standards as in previous years. The goal is that students who earn 5s this year are just as strong as those who earned 5s in any other year.
The table below gives a rough idea of the raw percentage scores required for each level of AP score:
These percentages will be used to score your practice exams in this book. You will receive your actual AP grade in early July.
How Do I Register and How Much Does It Cost?
If you are enrolled in AP Physics in your high school, your teacher will provide all of these details, but a quick summary here can’t hurt. After all, you do not have to enroll in the AP course to register for and complete the AP exam. When in doubt, the best source of information is the College Board’s Web site: www.collegeboard.com.
Currently, the fee for taking the exam is about $100. Students who demonstrate financial need may receive a refund to offset the cost of testing. The fee and the refund usually change a little from year to year. You can find out more about the exam fee and fee reductions and subsidies from the coordinator of your AP program or by checking information on the official Web site: www.collegeboard.com.
I know that seems like a lot of money just for a test. But, you should think of this $100 as the biggest bargain you’ll ever find. Why? Most colleges will give you a few credit hours for a good score. Do you think you can find a college that offers those credit hours for $100? Usually you’re talking hundreds of dollars per credit hour! You’re probably saving thousands of dollars by earning credits via AP.
There are also several optional fees that must be paid if you want your scores rushed to you or if you wish to receive multiple-grade reports. Don’t worry about doing that unless your college demands it. (What, you think your scores are going to change if you don’t find them out right away?)
The coordinator of the AP program at your school will inform you where and when you will take the exam. If you live in a small community, your exam may not be administered at your school, so be sure to get this information.
What If My School Doesn’t Offer AP Physics 2?
If your school does not offer AP Physics 2, you can study for the exam on your own. This review guide will put you on the right path to success. However, there are two additional things you can do when preparing on your own.
1. Ask the physics teacher (AP Physics 1 teacher, if the course is offered) at your school to supply you with some official College Board AP Physics 2 released questions that you can work through. Don’t ask for the key! Just ask for the questions. Looking at the key, instead of actually working the problems, fools you into thinking you know what you are doing when really you’re just looking at someone else’s work. Once you have worked the problems, have the teacher grade them for you and give you advice. Most teachers are more than happy to help motivated students.
2. If you don’t already have one, get a good noncalculus-based, college-level physics textbook. The College Physics: A Strategic Approach by Randal Knight, Brian Jones, and Stuart Field, and College Physics by Eugenia Etkina, Michael Gentile, and Alan Van Heuvelen are good choices for AP Physics 2. If you can’t find one, check one out from the library or ask a physics teacher at your school. Read through all the chapters covering the content you find in this review guide.
What Should I Bring to the Exam?
On exam day, I suggest bringing the following items:
• Several pencils and an eraser that doesn’t leave smudges.
• Black- or blue-colored pens for the free-response section.1
• A ruler or straightedge.
• A scientific calculator with fresh batteries. (A graphing calculator is not necessary.)
• A watch so that you can monitor your time. You never know if the exam room will have a clock on the wall. Make sure you turn off the beep that goes off on the hour.
• Your photo identification.
• Your quiet confidence that you are prepared.
What Should I NOT Bring to the Exam?
Leave the following at home:
• Phone, smart watch, and anything that can connect to the Internet.
• Books, a dictionary, study notes, flash cards, highlighting pens, correction fluid, etc., including this book. Study aids won’t help you the morning of the exam . . . end your studying in the early evening the night before.
• Portable music of any kind.
• Clothing with any physics terminology or equations on it.
• Panic or fear. It’s natural to be nervous, but you can comfort yourself that you have used this book well and that there is no room for fear on your exam.
1You may use a pencil, but you should not erase incorrect work, you should cross it out. Not only does crossing out take less time than erasing, if you erase something important by mistake, you lose all your work. If you happen to change your mind about crossing something out, just circle your work and write the reader a note: “Grade this!”