5 Steps to a 5: AP Physics 1: Algebra-Based 2017 (2016)

STEP 3

Develop Strategies for Success

CHAPTER 9

Strategies to Approach the Questions: Multiple-Choice Section

IN THIS CHAPTER

Summary: Even the multiple-choice section of the AP Physics 1, Algebra-Based Exam contains types of questions you probably have not encountered before. This chapter contains strategies and tips to attack the multiple-choice questions, including the new “multiple-correct” questions.

Key Ideas

   The multiple-choice section contains 50 questions, which require the same sorts of in-depth reasoning as the free-response questions.

   There’s no guessing penalty, so be sure you mark an answer to every item.

   Some questions will be identified as “multiple-correct” questions. For these, you need to choose exactly two answers. There’s no partial credit—you have to mark both of the correct answers, and neither of the wrong answers, to earn your point.

   To prepare for the test, practice pacing yourself using multiple-choice problems, and for the ones you miss, write explanations or justifications for the correct answers. This will truly allow you to learn from your mistakes.

Multiple-Choice Questions

The multiple-choice section comes first. You have 90 minutes to answer 50 questions. Each question will include four choices (not five, as on the old AP Physics B Exam). There’s no guessing penalty, so be sure you mark an answer to every item.

Before even thinking about strategies, understand that multiple-choice questions require the same sort of in-depth reasoning as do the free-response questions. The only difference is that you’re not expected to write out justification for your answers. You will see graphs, calculations, lab questions, ranking tasks, and explanations—everything that you’re used to from your physics class and everything that you could see on the free-response section. Don’t try to breeze through or to “game” the test. Just answer carefully, justifying each answer in your mind with a fact, equation, or calculation.

You have nearly two minutes per multiple-choice question. Some answers will be obvious; knock these out quickly, so that you leave more time to look at the more complicated questions.

Multiple-Correct: A New Question Type

Probably every multiple-choice test you’ve ever taken has asked you to pick the best answer from four or five choices for each problem. Well, that’s gonna change.

A subsection of five questions on the multiple-choice section will include “multiple-correct” questions. For these, you will be asked to choose exactly two answers. There’s no partial credit here—you have to mark both of the correct answers, and neither of the wrong answers, to earn your point.

These multiple-correct items replace the old-style questions with roman numerals I, II, and III. Also note that AP Physics 1, Algebra-Based multiple-choice questions will never ask something like, “Which of the following is notcorrect?” The College Board decided that multiple-correct questions were far easier to read and understand than the more confusing styles of past questions. This is supposed to be a physics test, after all, not a set of Hobbit-style riddles.

You will always know which questions are “multiple correct” as opposed to “single answer.” The only change to your approach on multiple-correct questions should be that you can’t eliminate the three wrong answers to find the one right answer—you have to consider each of the four choices on its own merits.

Example: A cart on a track is moving to the right and has been moving to the right for the last 2 s. Choose the correct statements about physical quantities related to the cart. Select two answers.

(A)   The cart’s displacement vector for the 2 s of motion is directed to the right.

(B)   The cart’s instantaneous velocity vector is directed to the right.

(C)   The net force acting instantaneously on the cart is directed to the right.

(D)   The cart’s average acceleration over the 2 s of motion is directed to the right.

This question requires just a bit more mental discipline than a standard multiple-choice item. Start by looking at choice (A). Displacement means, where does the cart end up in relation to its starting point? The cart ended up to the right of where it started, so the displacement is to the right. Mark choice (A).

In standard multiple-choice questions, you’d be done, dusted, and reading the next question by now. Not here, though. Keep reading. (B) The direction of instantaneous velocity is simply the direction that the cart is moving in right now. That’s also to the right. Also mark choice (B).

Then look at (C) and (D). The direction of acceleration cannot be determined unless we know whether the cart is speeding up or slowing down. Net force is always in the direction of acceleration; because the acceleration direction is unknown, so is the net force direction. Don’t mark choices (C) or (D).

Preparing for the Multiple-Choice Section of the Test

Pacing Yourself

Your physics teacher has access to all sorts of multiple-choice questions that are at least somewhat similar to what you’ll see on the AP Physics 1 exam. A full practice AP Physics 1 test is available to teachers. And, teachers will be able to see and use questions from the international version of the first few AP Physics 1 exams. But you and your teacher shouldn’t limit yourselves just to authentic AP Physics 1 questions. Items from released AP Physics B exams since the mid 2000s are usually close to the style of AP Physics 1. You likely have or will see questions from these sources on your in-class tests, your semester exam, or in practice packets. Use your in-class multiple-choice questions as preparation for the real AP Physics 1 Exam.

Whatever you do, don’t look at a big set of multiple-choice questions at your leisure, trying them and looking up the answers. Instead, take a set of multiple-choice questions as an authentic test. The real exam gives 50 questions in 90 minutes; so you should attempt 25 questions in 45 minutes, for example, or 16 questions in 30 minutes.

Do enough of these practice tests, and you’ll learn the correct pace. Are you getting to all the questions? If not, you’re going to need to decide your strengths and weaknesses. You’ll figure out before the real exam which types of problems you want to attempt first. You’ll learn through practice when you’re lingering too long on a single problem.

Test Corrections—The Best Way to Prepare for the Test

When you’re done with a practice test, don’t look up the solutions yet. Have someone else check your answers. For each problem you got wrong, talk to a friend about the problem. Either alone or with your friend’s help, write out a justification for the correct answer as if this were the free-response exam. Take about half a page for each justification. Have someone else, like your teacher, check your work again, marking the justifications that still are incomplete or incorrect. Do these again , even if you need a lot of help.

The point is, in preparing for the exam it is way too easy to fool yourself into thinking you understand a problem if you look at the solutions too soon. That’s why your physics class gives tests—not just to put a grade on the report card, but to give you authentic feedback on what you know, and what you need to work on. If you are thorough and careful in correcting your in-class and practice tests, you will find your multiple choice scores improving rapidly. (But if you show up on exam day without ever taking a practice exam and doing corrections, you will be doing a lot of guessing.)

Final Strategies for the Multiple-Choice Section

Here are some final strategies and advice that will help you score higher on the multiple-choice section of the AP Physics 1 Exam:

  • Never try to “game” the test. Don’t approach a question thinking, “What do they1 want me to say?” There is no trick, no ulterior motive in the question. Just show your physics knowledge, or take your best guess.
  • The multiple-choice questions will not necessarily start easy and get harder (unlike those on the SAT which start easy and get hard). If you suspect from your practice that you may be pressed for time, know that the problems on your strong topics may be scattered throughout the exam. Problem 50 may be easier for you than problem 5, so pace yourself so that you can get through the whole test and at least get all the easy answers right.
  • If you don’t see a direct approach to answering a question, look at the choices. They might give you a hint. For example, one of the choices might be way too fast for a car to be moving, or one of the explanations of a concept might contain an obvious error. Then, great, you can eliminate the obvious “stupidicism,” guess from the other choices, and move on. Don’t dwell on a single question.
  • There are no trick questions on this exam. An answer choice cannot “deny the stem.” This means, if a problem asks “Which of the following evidence shows that momentum is conserved in this situation?” one answer choice will not be “Momentum wasn’t even conserved.”
  • Often a good guess is evidence of good physics instincts. Don’t be afraid to make a guess based on your intuition. If you’ve been practicing physics problems appropriately and you’ve been correcting your practice tests, then your instincts will be finely honed by exam time. What you call a “guess” may well be much better than a shot in the dark.

1 Who do you mean by “they” anyway? The test is written by some of the country’s best physics teachers. Their job is to test whether you know physics, not to show how clever they are, not to embarrass you, and not to play “gotcha!”