SAT Subject Physics Practice Question 7: Answer and Explanation
7. A soccer ball, at rest on the ground, is kicked with an initial velocity of 10 m/s at a launch angle of 30°. Calculate its total flight time, assuming that air resistance is negligible.
A. 0.5 s
B. 1 s
C. 1.7 s
D. 2 s
E. 4 s
Correct Answer: B
First we determine the time required for the ball to reach the top of its parabolic trajectory (which is the time required for the vertical velocity to drop to zero).
The total flight time is equal to twice the following value: