Mechanics problem. A bottle is dropped from a blimp whose height is 1200m. Assume that a= 9.81m/s/s, find the time it takes the bottle to reach the ground.

The position of the bottle is given by the equation: $s=s_0-\dfrac{1}{2}gt^2$ where $s_0= 1200m $ is the starting point. And it is at the ground whan $s=0$, i.e: $s_0=\dfrac{1}{2}gt^2$. Solving for $t$ you have $t=\sqrt{2s_0/g}$