[tex]Dane:\\v_{o}=0\\h = 8 \ m\\g = 10\frac{m}{s}\\Szukane:\\v = ?\\\\Rozwiazanie\\\\Z \ zasady \ zachowania \ energii\\\\E_{p} = E_{k}\\\\mgh = \frac{mv^{2}}{2} \ \ /\cdot\frac{2}{m}\\\\v^{2} = 2gh\\\\v = \sqrt{2gh}\\\\v = \sqrt{2\cdot10\frac{m}{s^{2}}\cdot8 \ m}\\\\\boxed{v\approx12,65\frac{m}{s}}[/tex]
