A boy throws a stone straight upward with an initial speed of 15m/s. What maximum height will the stone reach before falling back down?

[tex]height=\frac{velocity^2}{2gravity}\\\\
velocity=15\frac{m}{s}\\\\
g=9,8\frac{m}{s^2}\\\\height=\frac{15^2}{2*9,8}=\frac{225}{19,6}\\\\
\boxed{height=11,48\ meters}[/tex]