6.
[tex]Dane:\\v_1 = 4\frac{m}{s}\\v_2 = 10\frac{m}{s}\\t = 4 \ s\\Szukane:\\a = ?\\\\\\a = \frac{\Delta v}{t} = \frac{v_2-v_1}{t} = \frac{10\frac{m}{s}-4\frac{m}{s}}{4 \ s} = \frac{6\frac{m}{s}}{4 \ s}\\\\\boxed{a = 1,5\frac{m}{s^{2}}}[/tex]
7.
[tex]Dane:\\v_{o} = 0\\t = 3 \ min \ \ 20 \ s = 3\cdot60 \ s + 20 \ s = 180 \ s + 20 \ s = 200 \ s\\a = 0,1\frac{m}{s^{2}}\\Szukane:\\s = ?\\\\\\s = \frac{1}{2}at^{2}\\\\s = \frac{1}{2}\cdot0,1\frac{m}{s^{2}}\cdot(200\frac{m}{s})^{2}} =\frac{1}{2}\cdot0,1\frac{m}{s^{2}}\cdot40000\frac{m^{2}}{s^{2}}\\\\\boxed{s = 2 \ 000 \ m = 2 \ km}[/tex]