Question

Hideki throws a baseball ball upward with an initial velocity of 12 meters/sec. When he throws the ball, it is two meters above the ground. How long will it take the ball to hit the ground?

Answer 1

-4.9^2 + 12t + 2 = 0

Explanation:

Answer 2

For this case we have the following kinematic equation that models the problem:
h (t) = (1/2) * (- 9.8) * t ^ 2 + 12 * t + 2
Rewriting we have:
h (t) = -4.9 * t ^ 2 + 12 * t + 2
When the ball hits the ground we have:
-4.9 * t ^ 2 + 12 * t + 2 = 0
Solving the polynomial we have:
t1 = -0.16
t2 = 2.61
We ignore the negative root because it is time.
Answer:
It will take the ball to hit the ground about:
t = 2.61 sec