How long is a ball in air when thrown up from 25m at 11 m/s?

[sp00ky]

A ball is thrown straigh up, from height of 25 m above the ground, at a speed of 11 m/s.
The first question is what is the max. height of the ball above the ground.
I got that one it's like 31m. But there was another question after that that asks how long is the ball in the air. What equation must I use to find this out?

 

[daster]

When does the ball 'stop' being in the air?

 

[Achtung]

well first find the time taken to reach the max ht. double this time it is the time taken for the ball to reach the ht it was thrown from(25m ) at this pt the ball has a speed of 11m/s use s =ut+4.9t^2 to find this t2 add this to t1 and that is the time taken to reach the ground. to find time to reach max ht use v = u+at.