2.
a)
[tex]t = 0,2 \ h = 0,2\\s = 15 \ km\\\\v = \frac{s}{t}\\\\v = \frac{15 \ km}{0,2 \ h}\\\\v = 75 \frac{km}{h}\\\\75\frac{km}{h} = 75:3,6\frac{m}{s} \approx20,83\frac{m}{s}\\\\\boxed{v = 75\frac{km}{h}\approx20,83\frac{m}{s}}[/tex]
b)
[tex]s = 900 \ m\\t = 180 \ s\\\\v = \frac{s}{t}\\\\v = \frac{900 \ m}{180 \ s}\\\\\boxed{v=5\frac{m}{s}}[/tex]
4.
a)
[tex]v = 5,4\frac{km}{h} = 5,4:3,6\frac{m}{s} = 1,5\frac{m}{s}\\t = 10 \ s\\\\s = v\cdot t\\\\s = 1,5\frac{m}{s}\cdot10 \ s\\\\\boxed{s = 15 \ m}[/tex]
b)
[tex]v = 16\frac{m}{s}\\t = 2 \ h = 2\cdot3600 \ s = 7200 \ s\\\\s = v\cdot t\\\\s = 16\frac{m}{s}\cdot7200 \ s\\\\\boxed{s = 115 \ 200 \ m = 115,2 \ km}[/tex]
