Data: Final velocity = 11.176m/s (or 25 mi/hr)
Firstly, we need to replace our values on the third given equation. It is convenient to use all the values on their SI units.
[tex]11.176^2=0^2-2*9.81*\Delta x\Rightarrow\Delta x=\frac{11.176^2}{-2*9.81}=-6.366m[/tex]Thus, the ball would need to be dropped from a height of 6.366m, or 20.89ft