[tex]Dane:\\m = 500 \ g = 0,5 \ kg\\t = 50 \ s\\\Delta v = 30\frac{m}{s}\\Szukane:\\F_{w}=?\\\\Rozwiazanie\\\\\underline{F_{w} = m\cdot a}\\\\a = \frac{\Delta v}{t} = \frac{30\frac{m}{s}}{50 \ s} = 0,6\frac{m}{s^{2}}\\\\F_{w} = 0,5 \ kg\cdot0,6\frac{m}{s^{2}}\\\\\boxed{F_{w} = 0,3 \ N}[/tex]
