Odpowiedź:
[tex]\huge\boxed{v = 27\frac{km}{h}}[/tex]
Obliczenia:
[tex]Dane:\\F = 20 \ N\\P = 0,15 \ kW = 0,15\cdot1000 \ W = 150 \ W\\Szukane:\\v = ?\\\\Rozwiazanie[/tex]
Korzystamy ze wzoru na moc:
[tex]P = \frac{W}{t} = \frac{F\cdot s}{t} = F\cdot v\\\\P = F\cdot v \ \ \ /:F\\\\v = \frac{P}{F}\\\\v = \frac{150 \ W}{20 \ N} = \frac{150 \ kg\cdot\frac{m^{2}}{s^{3}}}{20 \ kg\cdot \frac{m}{s^{2}}}\\\\v = 7,5\frac{m}{s}=7,5\cdot\frac{\frac{1}{1000} \ km}{\frac{1}{3600} \ h} = 7,5\cdot3,6\frac{km}{h} =27\frac{km}{h}\\\\\boxed{v = 27\frac{km}{h}}[/tex]
