1.
[tex]Dane:\\t=4 \ s\\s = 10 \ m\\Szukane:\\a = ?\\\\s = \frac{at^{2}}{2} \ \ /\cdot\frac{2}{t^{2}}\\\\a = \frac{2s}{t^{2}}\\\\a = \frac{2\cdot10 \ m}{(4 \ s)^{2}}\\\\\boxed{a = 1,25 \ \frac{m}{s^{2}} \ - \ opoznienie}[/tex]
2.
[tex]Dane:\\v_{o} = 20\frac{km}{h}\\t = 2 \ min = 2\cdot60 \ s = 120 \ s\\v = 100\frac{km}{h}\\Szukane:\\a = ?\\\\a = \frac{\Delta v}{t} \\\\\Delta v =v-v_{o} \\\\\Delta v = 100\frac{km}{h}-20\frac{km}{h} = 80\frac{km}{h} = 80\cdot\frac{1000 \ m}{3600 \ s} =22,(2)\frac{m}{s} = 22,22\frac{m}{s}\\\\a = \frac{22,22\frac{m}{s}}{20 \ s}\\\\\boxed{a = 1,11\frac{m}{s^{2}}}[/tex]
