How Fast Did Nicole Throw the Ball?

[zellster87]

Homework Statement

This problem has really been bugging me, and i can't seem to figure it out. Heres the question:

Nicole throws a ball straight up. Chad watches the ball from a window 5.90 m above the point where Nicole released it. The ball passes Chad on the way up, and it has a speed of 15.0 m/s as it passes him on the way back down.

How fast did nicole throw the ball?

I don't understand how the guy in the window at 4.9m meters helps me at all. Any help will be greatly apprectiated. Thanks.

Homework Equations

V final = V initial + a(delta t)

The Attempt at a Solution

 

[mgb_phys]

See https://www.physicsforums.com/showthread.php?t=209642