A Tennis Ball Is Thrown from Ground Level with Velocity

Multiple Choice

A tennis ball is thrown from ground level with velocity v₀ directed 30° above the horizontal. If it takes the ball 0.5 s to reach the top of its trajectory, what is the magnitude of the initial velocity?

A) 4.9 m/s
B) 9.8 m/s
C) 11.3 m/s
D) 19.6 m/s
E) 34.4 m/s