[tex]dane:\\v = 72\frac{km}{h} = 72\cdot\frac{1000 \ m}{3600 \ s} = 20\frac{m}{s}\\F = 1 \ 400 \ N\\szukane:\\P = ?\\\\Rozwiazanie\\\\P = \frac{W}{t} = \frac{F\cdot s}{t} = F\cdot v\\\\P = 1400 \ N \cdot20\frac{m}{s}=1400 \ kg\cdot\frac{m}{s^{2}}\cdot20\frac{m}{s} = 28000 \ kg\cdot\frac{m^{2}}{s^{3}}\\\\P = 28 \ 000 \ W = 28 \ kW[/tex]
