Simple kinematics problem(i need help)

[sz1989]

Homework Statement

I throw a ball vertically out of a 84meter high window with an intial velocity of 32.2m/s. How many seconds until the ball hits the ground

Homework Equations

The Attempt at a Solution

 

[robertm]

You have to give us an idea of what you have tried to solve this problem before anyone will help you.

Apparently you understand that this is a kinematics problem, so start from there. What Kinematic equations do you know, and what one do you think will apply to describe this situation?