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Introduction to SAT II Physics - FreeExamPapers

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negative, so E, and not A, is the correct graph.<br />

The answer <strong>to</strong> question 3 is D. The acceleration due <strong>to</strong> gravity is constant throughout the ball’s<br />

trajec<strong>to</strong>ry, and since it is in a downward direction, its value is negative.<br />

Don’t worry if the question confused you and the explanations didn’t help. This material and more<br />

will be covered in Chapter 2: Kinematics. This was just an exercise <strong>to</strong> show you how a<br />

classification question is formatted.<br />

Part B: Five-Choice Completion Questions<br />

These are the multiple-choice questions we all know and love, and the lifeblood of any multiplechoice<br />

exam. You know the drill: they ask a question, give you five possible answer choices, and<br />

you pick the best one. Got it? Good. An example appears below.<br />

While you’ll often find two or three questions in a row that deal with the same <strong>to</strong>pic in physics,<br />

there is no pattern. You might find a question on modern physics followed by a question on<br />

dynamics followed by a question on optics. However, there is a general tendency for the questions<br />

<strong>to</strong> become more difficult as you progress.<br />

Five-Choice Completion Question Example<br />

Directions: Each of the questions of incomplete statements below is followed by five<br />

suggested answers or completions. Select the one that is best in each case and then fill in<br />

the corresponding oval on the answer sheet.<br />

1. . A gas in a closed container is steadily heated over a period of time. Which of the following<br />

statements is true of this process?<br />

(A) The average kinetic energy of the gas molecules decreases<br />

(B) The mass of the container increases<br />

(C) The pressure exerted by the gas on the walls of the container increases<br />

(D) The gas changes phase in<strong>to</strong> a liquid<br />

(E) The specific heat of the gas decreases<br />

Explanation<br />

The answer <strong>to</strong> this question is C. The key lies in remembering the ideal gas law: PV = nRT.<br />

According <strong>to</strong> this formula, an increase in temperature is accompanied by an increase in pressure. A<br />

is wrong, since the average kinetic energy of gas molecules corresponds <strong>to</strong> their temperature: if<br />

the temperature increases, so does the average kinetic energy of the molecules. B is wrong because<br />

we’re dealing with a closed container: the mass cannot either increase or decrease. D is wrong<br />

because a gas must be cooled, not heated, <strong>to</strong> change phase in<strong>to</strong> a liquid. Finally, E is wrong<br />

because the specific heat of any substance is a constant, and not subject <strong>to</strong> change. We’ll <strong>to</strong>uch on<br />

all this and more in Chapter 9: Thermal <strong>Physics</strong>.<br />

How Your Knowledge Will Be Tested<br />

There are three different levels on which your understanding of physics may be tested. While<br />

questions on kinematics often require that you make use of some of the formulas for kinematic<br />

motion, questions on quantum physics or a<strong>to</strong>mic structure may often ask just that you remember<br />

the name of a particular concept. Knowing the different ways in which your knowledge may be<br />

tested should help you better prepare yourself for the exam.<br />

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