A bocce ball is accidentally dropped from a building 98m high. How long does it take for the bocce ball to hit the ground, given that the acceleration due to gravity is 9.8 meters per second per second?

I took

s(t)=-4.9t^2 + 9.8 = 0

Solved for t

-4.9t^2 = -9.8

t^2=2

t=sqrt(2)=1.414 seconds.

I had to enter my answer into a computer checking system, and it says that my answer is wrong. What am I doing wrong?