[tex]dane:\\m = 1000 \ kg\\v_{o} = 0\\t = 15 \ s\\v = 30\frac{m}{s}\\szukane:\\F_{w} = ?\\\\Z \ II \ zasady \ dynamiki\\\\a = \frac{F{w}}{m} \ \ /\cdot m\\\\F_{w} = m\cdot a\\\\a = \frac{\Delta v}{t} = \frac{v-v_{o}}{t} = \frac{v}{t} = \frac{30\frac{m}{s}}{15 \ s} = 2\frac{m}{s^{2}}\\\\F_{w} = 1000 \ kg\cdot2\frac{m}{s^{2}}\\\\F_{w} = 2 \ 000 \ N = 2 \ kN[/tex]
