[tex]Dane:\\m = 25 \ kg\\v = 12\frac{m}{s}\\Szukane:\\E_{m} = ?\\\\E_{m} = E_{p}+E_{k}\\\\E_{p}= 0, \ zatem\\\\E_{m} = E_{k}\\\\E_{k}=\frac{1}{2}mv^{2}\\\\E_{k}=\frac{1}{2}\cdot25 \ kg\cdot(12\frac{m}{s})^{2}}\\\\E_{k} = \frac{1}{2}\cdot25 \ kg \cdot 144\frac{m^{2}}{s^{2}}\\\\E_{k} = 1 \ 800 \ J = 1 , 8 \ kJ\\\\\boxed{E_{m} = E_{k} = 1,8 \ kJ}[/tex]
