11.
[tex]dane:\\m = 10 \ kg\\F = 100 \ N\\T = 90 \ N\\szukane:\\a = ?\\\\Rozwiazanie\\\\Z \ II \ zasady \ dynamiki\\\\a = \frac{F_{w}}{m}\\\\F_{w} = F-T = 100 \ N - 90 \ N = 10 \ N\\\\a = \frac{10 \ N}{10 \ kg} =1\frac{N}{kg} =1\frac{m}{s^{2}}[/tex]
12.
[tex]dane:\\v_{o} = 0\\t = 100 \ s\\v = 20\frac{m}{s}\\F = 100 \ N\\szukane:\\m = ?\\\\Rozwiazanie\\\\a = \frac{\Delta v}{t} = \frac{v-v_{o}}{t} = \frac{v}{t} = \frac{20\frac{m}{s}}{100 \ s} = 0,2\frac{m}{s^{2}} = 0,2\frac{N}{kg}\\\\a = \frac{F}{m} \ \ \Rightarrow \ \ m = \frac{F}{a}\\\\m = \frac{1000 \ N}{0,2\frac{N}{kg}} = 500 \ kg[/tex]
