An airplane taking off from a runway travels 3600 feet before lifting off. If it starts from rest, moves with constant acceleration, and makes the run in 30 seconds, with what speed does it lift off?

I know that velocity is the first derivative of the position function, and acceleration is the second, but what is the position function?

Is it $\displaystyle f(t)=-16t^2+v0t+s0?$