Freefall: Solving Questions with Initial Velocity of 20 m/s

[kitle545]

I don't know how to do this problem. I feel like I need more information.

A ball is thrown upward with an initial velocity of 20 m/s.

1. How long is the ball in the air?

2. How long after release is the ball 15 m above the release point?

 

[edziura]

For #1:

What is the initial velocity?
What is the velocity when the ball reaches the top of its upward travel?
what is the acceleration due due gravity?
Is the time taken to reach the top of its upward travel equal to the time to return to earth?