Calculating Time and Angle of Impact in Free Fall Physics Problem

[laladude]

Homework Statement

http://i1120.photobucket.com/albums/l498/LaLadude/2.jpg

How long does it take to reach the ground? And what is the angle of impact with the ground?

Homework Equations

The Attempt at a Solution

Δy = Vo_y * t + (1/2)a_y * t²
t = (-5 m/s) ± √(5 m/s)² - 4(1/2)(-9.81 m/s²)(-100m) / 2(1/2)(-9.81 m/s²)

t = -5 m/s ± (4.54)

Is it suppose to be 4.54 or -4.54? And am I suppose to add or subtract the two variables to find t??

 

[sandy.bridge]

Post the entire question.

 

[laladude]

Post the entire question.

I added a picture link if it'll help.