SAT II Physics is a one-hour-long test composed of 75 questions and divided into two parts. You can answer questions in any order you like, though you’re less likely to accidentally leave a question out if you answer them in the order in which they appear. Part A—classification questions—takes up the first 12 or 13 questions of the test, while Part B—five-choice completion questions—takes up the remaining 62 or 63 questions.
Part A: Classification Questions
Classification questions are the reverse of normal multiple-choice question: they give you the answers first and the questions second. You’ll be presented with five possible answer choices, and then a string of two to four questions to which those answer choices apply. The answer choices are usually either graphs or the names of five related laws or concepts. Because they allow for several questions on the same topic, classification questions will ask you to exhibit a fuller understanding of the topic at hand.
The level of difficulty within any set of questions is generally pretty random: you can’t expect the first question in a set to be easier than the last. However, each set of classification questions is generally a bit harder than the one that came before. You should expect questions 11–13 to be harder than questions 1–4.
Classification Question Example
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Directions: Each set of lettered choices below refers to the numbered questions immediately following it. Select the one lettered choice that best answers each question and then blacken the corresponding space on the answer sheet. A choice may be used once, more than once, or not at all in each set.
Questions 1–3
A boy throws a ball straight up in the air and then catches it again.
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| 1. |
Which of the above graphs best represents the ball’s position with respect to time? |
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| 2. |
Which of the above graphs best represents the ball’s velocity with respect to time? |
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| 3. |
Which of the above graphs best represents the ball’s acceleration with respect to time? | |
Explanation
You can usually answer classification questions a bit more quickly than the standard five-choice completion questions, since you only need to review one set of answer choices to answer a series of questions.
The answer to question 1 is B. The ball’s position with respect to time can be expressed by the equation y = –1/2 gt2, where g is the downward, acceleration due to gravity. As we can see, the graph of y against t is an upside-down parabola. In more intuitive terms, we know that, over time, a ball thrown in the air will rise, slow down, stop, and then descend.
The answer to question 2 is E. The acceleration due to gravity means that the velocity of the ball will decrease at a steady rate. On the downward half of the ball’s trajectory, the velocity will be negative, so E, and not A, is the correct graph.
The answer to question 3 is D. The acceleration due to gravity is constant throughout the ball’s trajectory, and since it is in a downward direction, its value is negative.
Don’t worry if the question confused you and the explanations didn’t help. This material and more will be covered in Chapter 2: Kinematics. This was just an exercise to show you how a classification question is formatted.
