A ball is thrown 125 meters upward and then falls the same distance back to Earth. Neglecting air resistance, its total time in the air is

the ball is in the air for 10 seconds

Explanation:

let gravity = 10m/s/s

height = 1/2 acceleration • time^2

125 m = 1/2 •  10 m/s/s • time ^2

125m = 5 m/s/s • time^2

25s = time^2

5 s = time

5 seconds is the time required for half of the flight

time total = 2 • time

time total = 2 • 5s

time total = 10 s

probably not if net force is zero