[tex]m_1 = 70 \ kg\\m_2 = 850 \ kg\\m = m_1+m_2 = 70 \ kg + 850 \ kg = 920 \ kg\\a = 5,8\frac{m}{s^{2}}\\Szukane:\\F_{w} = ?\\\\Rozwiazanie\\\\Z \ II \ zasady \ dynamiki:\\\\F_{w} = m\cdot a\\\\F_{w} = 920 \ kg\cdot5,8\frac{m}{s^{2}}\\\\\boxed{F_{w} = 5 \ 336 \ N = 5,336 \ kN}[/tex]