[tex]dane:\\m = 80 \ kg\\v = 25\frac{km}{h} = 25\cdot\frac{1000 \ m}{3600 \ s} \approx6,94\frac{m}{s}\\szukane:\\E_{k} = ?\\\\E_{k} = \frac{1}{2}mv^{2}\\\\E_{k} = \frac{1}{2}\cdot80 \ kg\cdot(6,94\frac{m}{s})^{2}\\\\E_{k}\approx1 \ 926,5 \ J \approx 1 \ 927 \ J[/tex]
