[tex]Dane:\\P = 2 \ kW = 2 \ 000 \ W\\F = 800 \ N\\Szukane:\\v = ?\\\\Rozwiazanie\\\\P = \frac{W}{t}\\\\ale \ \ W = F\cdot s\\\\P = F\cdot\frac{s}{t} = F\cdot v\\\\P = F\cdot v \ \ /:F\\\\v = \frac{P}{F}\\\\v = \frac{2000 \ W}{800 \ N} = \frac{2000 \ kg\cdot\frac{m^{2}}{s^{3}}}{800 \ kg\cdot\frac{m}{s^{2}}}\\\\\boxed{v = 2,5\frac{m}{s}}[/tex]
