-- Mr. Galonski looks at himself in the mirror while he shaves in the morning, using visible light.
-- On his way to work, he listens to music and news, taking advantage of all the radio waves around.
-- While walking from his car to his office, he takes his jacket off and rolls up his sleeves, so his arms can soak up some ultraviolet from the sun, and get a little bit of color.
-- Mister Galonski is actually DOCTOR Galonski DDS ... a dentist. He uses a machine that produces X-rays, to take pictures of his patients' teeth and jaws. He glues the pictures into a big scrap-book that he keeps on the coffee table in his living room.
Answer:
(I). The time at highest point 4.0 sec.
(II). It returns to back to its original height in 8.1 sec
Explanation:
Given that,
Velocity 
(I). We need to calculate the time at highest point
Using equation of motion

Where, v = final velocity
u = initial velocity
g = acceleration due to gravity
t = time
Put the value into the formula




(II). We know that, when the ball to travel from the initial point and reached at initial point then the displacement is zero.
We need to calculate the total time when it returns to back to its original height
Using equation of motion

Where, s = displacement
g = acceleration due to gravity
t = time
u = velocity
Put the value in the equation



Hence. (I). The time at highest point 4.0 sec.
(II). It returns to back to its original height in 8.1 sec
I would say its the last answer