Answer:
The ball spend
in the air.
Step-by-step explanation:
The angle which maximize the distance is
.
From Kinematics, the position in the component
as a function of time is:
, with
.
At
final, the ball will be in the ground and we'll have
.
So,
⇒

⇒
.
¿But what is the component in
of
,
?
This is
.
So, we finally have:
.