[tex]dane:\\m = 40 \g = 0,04 \ kg\\h = 3 \ m\\g = 10\frac{m}{s^{2}}\\szukane:\\v = ?\\\\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}}\cdot3 \ m} = \sqrt{60\frac{m^{2}}{s^{2}}}\\\\v \approx7,75\frac{m}{s}[/tex]
