0 m/s is it's initial speed.

to find the time,
you derive a formula from this: d=Vt + (0.5)(a)(t^2)
d-distance              t-time
V- initial velocity      a-acceleration due to gravity

-1.50m=(0m/s)(t) + (0.5)(-9.8 m/s^2)(t^2)   plug it in.
-1.50m= (-4.9 m/s^2)(t^2)                 Isolate t
(-1.50m)/(-4.9 m/s^2)=t^2                 
7.35 s=t^2                                           square root the evreything.
2.71108834 s= t
2.7 s= t

It takes approx. 2.7 seconds.

3 3 3
thank you very much!!!
I hope you understand. Knowing the process and the answer are two different things.