1.
[tex]dane:\\v_{o} = 0\\t = 2 \ s\\v = 60\frac{km}{h} = 60\cdot\frac{1000 \ m}{3600 \ s} = 16,(6)\frac{m}{s} = 16,67\frac{m}{s}\\v_1 = 100\frac{km}{h} = 100\cdot\frac{1000 \ m}{3600 \ s} = 27,(7)\frac{m}{s} = 27,78\frac{m}{s}\\szukane:\\t_1 = ?\\\\Rozwiazanie\\\\a = \frac{\Delta v}{t} = \frac{v}{t} = \frac{16,67\frac{m}{s}}{2 \\ s} = 8,34\frac{m}{s^{2}}\\\\v_1 =a\cdot t_1 \ \ /:a\\\\t_1 = \frac{v_1}{a}\\\\t_1 = \frac{27,78\frac{m}{s}}{8,34\frac{m}{s^{2}}} =3,3 \ s[/tex]
Odp. Szukany czas t₁ = 3,3 s.
2.
[tex]dane:\\v_{o} = 0\\s = 25 \ cm = 0,25 \ m\\t = 10 \ s\\szukane:\\a = ?\\\\Rozwiazanie\\\\s = \frac{at^{2}}{2} \ \ /\cdot2\\\\at^{2} = 2s \ \ /:t^{2}\\\\a = \frac{2s}{t^{2}}\\\\a = \frac{2\cdot0,25 \ m}{(10 \ s)^{2}} = \frac{0,5 \ m}{100 \ s^{2}}= 0,005\frac{m}{s^{2}}[/tex]
Odp. Szukane przyspieszenie a = 0,005 m/s².
