[tex]dane:\\m = 2 \ 000 \ kg\\v_1 = 10\frac{m}{s}\\v_2 = 20\frac{m}{s}\\szukane:\\\frac{E_{_2}}{E_{k_1}} = ?\\\\\\E_{k} = \frac{mv^{2}}{2}\\\\E_{k_1} = \frac{mv_1^{2}}{2}\\\\E_{k_2} = \frac{mv_2^{2}}{2}\\\\\frac{E_{k_2}}{E_{k_1}} = \frac{\frac{mv_2^{2}}{2}}{\frac{mv_1^{2}}{2}} = \frac{v_2^{2}}{v_1^{2}} = \frac{20^{2}}{10^{2}} = 2^{2} = 4\\\\E_{k_2} = 4E_{k_1}[/tex]
Odp. Energia kinetyczna wzrosła 4-razy wraz z kwadratem ilorazu prędkości.
