Question

Which equation would best help solve the following problem? Hideki throws a baseball ball upward with an initial velocity of 12 m/s. When he throws the ball, it is 2 m above the ground. How long will it take the ball to hit the ground? - 16t2 + 12+ + 2 = 0 -4.91? + 12+ + 2 = 0 2 -4.912 + 12t = 2 0 4.912 + 12t +2 = 0​

Answer 1

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