Answer:
After 0.75 seconds the ball would reach it's maximum height of 16 feet.
Explanation:
We are given a quadratic function
for height of the ball after T seconds.
We need to find the time T when ball would reach at it's maximum height and also maximum height of the ball.
In order to find the maximum height of the ball, we need to find the x-coordinate of the vertex.
x-coordinate of the vertex is given by formula
x =
.
For the given quadratic a=-16 and b= 24.
Plugging a=-16 and b= 24 in above formula of x-coordinate of the vertex.
.
Now, plugging x=0.75 in given quadratic
, we get

= -16(0.5625)+18+7
= -9+25
=16.
Therefore, after 0.75 seconds the ball would reach it's maximum height of 16 feet.