1.
[tex]Dane:\\v_1 = 20\frac{km}{h}\\t = 20 \ s\\v_2 = 100\frac{km}{h}\\Szukane:\\a = ?\\\\\\a = \frac{\Delta v}{t}\\\\\Delta v = v_2-v_1 = (100-20) \frac{km}{h} = 80\frac {km}{h}=80\cdot\frac{1000 \ m}{3600 \ s} = 22,22\frac{m}{s}\\\\a = \frac{22,22\frac{m}{s}}{20 \ s}\\\\\boxed{a =1,11\frac{m}{s^{2}}}[/tex]
2.
[tex]Dane:\\v_{o} = 0\\t = 2 \ min = 120 \ s\\a = 2\frac{m}{s^{2}}\\Szukane:\\v = ?\\\\\\v = at\\\\v = 2\frac{m}{s^{2}}\cdot120 \ s\\\\\boxed{v = 240\frac{m}{s}}[/tex]
3.
[tex]Dane:\\s = 10 \ m\\t = 4 \ s\\Szukane:\\a = ?\\\\\\s = \frac{at^{2}}{2} \ \ |\cdot2\\\\at^{2} = 2s \ \ /:t^{2}\\\\a = \frac{2s}{t^{2}}\\\\a = \frac{2\cdot10 \ m}{(4 \ s)^{2}} = \frac{20 \ m}{16 \ s^{2}}\\\\\boxed{a = 1,25\frac{m}{s^{2}}} \ - \ opoznienie[/tex]
