Answer:
50.0 m
Step-by-step explanation:
First of all, we can find the initial velocity of the ball, using the equation
v = u + at
where
v = 0 is the velocity of the ball at the highest position
u is the initial velocity
is the acceleration of gravity
is the time the ball took to reach the maximum height (half of the time it remained in the air)
Solving for u,

Now we can find the maximum height using the other SUVAT equation:

where d is the maximum height. Solving for d,
