[tex]dane:\\m_1 = m_2 = m\\v_1 = 15\frac{m}{s}}\\v_2 = 30\frac{m}{s} = 2v_1\\szukane:\\\frac{E_{k_2}}{E_{k_1}} = ?\\\\E_{k} = \frac{mv^{2}}{2}\\\\E_{k_1} = \frac{mv_1^{2}}{2}\\\\E_{k_2} = \frac{m\cdot(2v_1)^{2}}{2} = \frac{4mv_1^{2}}{2} = 2mv_1^{2}\\\\\frac{E_{k_2}}{E_{k_1}}=\frac{2mv_1^{2}}{\frac{mv_1^{2}}{2}}= 4\\\\E_{k_2} = 4E_{k_1}[/tex]
Odp. Energia samochodu wzrosła 4 razy.
