SAT Subject Physics Practice Question 338: Answer and Explanation
34. A girl standing on a high bridge over a creek throws a rock straight down at leaves floating in the creek. Just as she throws the rock she accidentally drops another rock. Neglecting air resistance, which statement best describes the situation just as the rocks reach the water?
A. The acceleration of the thrown rock is greater.
B. The acceleration of the dropped rock is greater.
C. The acceleration of both rocks is the same.
D. The average velocity of both rocks is the same.
E. The final velocity of both rocks is the same.
Correct Answer: C
The correct answer is (C). The starting velocity of the two rocks is not the same, but once in free fall the acceleration of the two rocks is equal.