[tex]Dane:\\m = 20 \ t = 20 \ 000 \ kg = 2\cdot10^{4} \ kg\\v = 20\frac{m}{s} = 2\cdot10\frac{m}{s}\\Szukane:\\E_{k} = ?\\\\Rozwiazanie\\\\E_{k}=\frac{1}{2}mv^{2}\\\\E_{k} = \frac{1}{2}\cdot2\cdot10^{4} \ kg\cdot(2\cdot10\frac{m}{s^{2}})^{2} =10^{4} \ kg\cdot4\cdot10\frac{m^{2}}{s^{2}}\\\\\boxed{E_{k} = 4\cdot10^{6} \ J = 4 \ MJ}\\\\(1 \ MJ = 1 \ 000 \ 000 \ J = 10^{6} \ J)[/tex]
