Respuesta :

Answer:

6 seconds

Step-by-step explanation:

h(x) = 0 m , when the ball is on the ground.

h(x) = - (x-2)² + 16

0 = - (x-2)² + 16

(x-2)² = 16

√(x-2)² = +/- √16

(x-2) = 4  ,        (x-2) = - 4

x - 2 = 4  ,         x = -2

x = 6

We can use only positive solution.