[tex]dane:\\v = 50\frac{m}{s}\\m = 20 \ g = 0,02 \ kg\\szukane:\\W = ?\\\\Rozwiazanie\\\\W = E_{k} = \frac{mv^{2}}{2}\\\\W = \frac{0,02 \ kg\cdot(50\frac{m}{s})^{2}}{2}\\\\W = 25 \ J[/tex]
