Homework Help: Physics/mechanics, forces accelaration

1. The problem statement, all variables and given/known data

A ball is thrown horizontal out of a window 18m above the ground. it is thrown horizontally at 5.0ms. show that it takes about 2 seconds to drop.

2. Relevant equations

S=ut+1/2at^2

3. The attempt at a solution

u=0
a=9.8
s=18
18=0t+1/2*9.8t^2
36=9.8t^2
sqrt3.6734=t
t=1.92

is this near enough too 2 to be the right answer or have i made a mistake some where i was not sure if the horizontal force would have any effect on the time taken to drop. Any help would be much appreciated.

 

Thanks i just needed conformation because i got to the answer partially using trial and error to find the right method and I'm impressed you managed to guess the exact next question on the paper.