1.
[tex]dane:\\t = 9 \ s\\s = 180 \ m\\szukane:\\v = ?\\\\v = \frac{s}{t} = \frac{180 \ m}{9 \ s} = 20\frac{m}{s}\\\\Odp. \ D.[/tex]
2.
[tex]v = 90\frac{km}{h}=\frac{90 \ km}{60 \ min} = 1,5\frac{km}{min}\\s = 60 \ km\\szukane:\\t = ?\\\\t = \frac{s}{v} = \frac{60 \ km}{1,5\frac{km}{min}} = 40 \ min\\\\Odp. \ C.[/tex]