[tex]Dane:\\m = 2 \ kg\\v_{p} = 1\frac{m}{s}\\t = 6 \ s\\v_{k} = 7\frac{m}{s}\\Szukane:\\F = ?\\\\Rozwiazanie\\\\F = m\cdot a\\\\ale\\\\a = \frac{\Delta v}{t} = \frac{v_{k}-v_{p}}{t} = \frac{(7-1)\frac{m}{s}}{6 \ s} = \frac{6\frac{m}{s}}{6 \ s} = 1\frac{m}{s^{2}}\\\\\\F = 2 \ kg\cdot1\frac{m}{s^{2}}\\\\\boxed{F = 2 \ N}[/tex]