Introduction to SAT II Physics - FreeExamPapers

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
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.
1. . Which of the above graphs best represents the ball’s position with respect to time?
2. . Which of the above graphs best represents the ball’s velocity with respect to time?
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 gt 2 , 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
10