Finding Time when throwing an object up

[SunKissedGal1]

Homework Statement

Standing on the top ledge of a 55 meter high building you throw a ball straight up with an initial speed of 35 m/s. How long, to the nearest second, does it take to hit the ground?

Homework Equations

v= at + v_o

The Attempt at a Solution

i think I am using the wrong equation...
X= 55
V= 35
a=9.8
t=?

 

[Weird Fishes]

Try using: d=v_ot +1/2at²

 

[LowlyPion]

Maybe if you figured how high it would go you could figure how long it will take to hit the ground from that total height? And then that added to how long it took to get to that height would be your total time wouldn't it?

 

[Weird Fishes]

Maybe if you figured how high it would go you could figure how long it will take to hit the ground from that total height? And then that added to how long it took to get to that height would be your total time wouldn't it?

Right, you would need, 2ad = vf²-vi²