1.
[tex]Dane:\\v_{o} = 7\frac{m}{s}\\t = 5 \ s\\v = 27\frac{m}{s}\\Szukane:\\a = ?\\\\a = \frac{\Delta v}{t}\\\\\Delta v = v-v_{o} = 27\frac{m}{s} - 7\frac{m}{s} = 20\frac{m}{s}\\\\a = \frac{20\frac{m}{s}}{5 \ s}\\\\\boxed{a = 4\frac{m}{s^{2}}}[/tex]
Jest to ruch jednostajnie przyspieszony, prostoliniowy.
2.
[tex]Dane:\\v_{o} = 0\\a = 6\frac{m}{s^{2}}\\v = 108\frac{km}{h} = 108\cdot\frac{1000 \ m}{3600 \ s} = 30\frac{m}{s}\\Szukane:\\t = ?\\\\a = \frac{\Delta v}{t} = \frac{v}{t} \ \ \rightarrow \ \ t = \frac{v}{a}\\\\t = \frac{30\frac{m}{s}}{6\frac{m}{s^{2}}}\\\\\boxed{t = 5 \ s}[/tex]
3.
[tex]Dane:\\v_{o} = 0\\a = 0,7\frac{m}{s^{2}}\\v = 2,1\frac{m}{s}\\\\a = \frac{v}{t} \ \ /\cdot t\\\\at = v \ \ /:a\\\\t = \frac{v}{t}\\\\t = \frac{2,1\frac{m}{s}}{0,7\frac{m}{s^{2}}}\\\\\boxed{t = 3 \ s}[/tex]
Jest to ruch jednostajnie przyspieszony, prostoliniowy.
