[tex]dane:\\P = 90 \ kW = 90 \ 000 \ W\\v = 108\frac{km}{h} = 108\cdot\frac{1000 \ m}{3600 \ s} = 30\frac{m}{s}\\szukane:\\F = ?\\\\P = \frac{W}{t} = \frac{F\cdot s}{t} = F\cdot v\\\\F\cdot v = P \ \ /:v\\\\F = \frac{P}{v}\\\\F = \frac{90000 \ W}{30\frac{m}{s}} = \frac{90000 \ kg\cdot\frac{m^{2}}{s^{3}}}{30\frac{m}{s}} = 3 \ 000 \ kg\cdot\frac{m}{s^{2}}\\\\F = 3 \ 000 \ N = 3 \ kN\\\\(1 \ kN = 1000 \ N)[/tex]
Odp. Siła silnika tego samochodu ma wartość 3 kN.
