[tex]dane:\\m = 2 \ g = 0,02 \ kg\\v = 700\frac{m}{s}\\szukane:\\E_{k} = ?\\\\E_{k} = \frac{1}{2}mv^{2}\\\\E_{k} = \frac{1}{2}\cdot0,02 \ kg\cdot(700\frac{m}{s})^{2}\\\\E_{k} = \frac{1}{2}\cdot0,02 \ kg \cdot490000\frac{m^{2}}{s^{2}}\\\\E_{k} = 4 \ 900 \ J = 4,9 \ kJ\\\\(1 \ kJ = 1000 \ J)[/tex]