A boy throws a ball with an initial velocity of 25 m/s at an angle of 30° above the horizontal.If air resistance is negligible,how high above the projection point is the ball after 2.0 s?
A)5.4 m
B)13 m
C)25 m
D)43 m
E)50 m

Question

Quizplus · Accepted Answer

The vertical component of the initial velocity is 25 m/s * sin(30°) = 12.5 m/s. After 2.0 s, the ball has traveled 12.5 m/s * 2.0 s = 25 m upward. The ball is also subject to gravity, which causes it to fall 4.9 m/s^2 * (2.0 s)^2 / 2 = 9.8 m downward. Therefore, the ball is 25 m - 9.8 m = 15.2 m above the projection point after 2.0 s.

A Boy Throws a Ball with an Initial Velocity of 25