W ruchu jednostajnym prostoliniowym prędkość jest wartością stałą:
[tex]v = \frac{s}{t} = constans \ \ \rightarrow \ \ s = v\cdot t \ \ \rightarrow \ \ t = \frac{s}{v}[/tex]
1.
[tex]Dane:\\t = 20 \ min = \frac{1}{3} \ h\\v = 18\frac{km}{h}\\Szukane:\\s = ?\\\\Rozwiazanie\\\\s = v\cdot t\\\\s = 18\frac{km}{h}\cdot\frac{1}{3} \ h\\\\\boxed{s = 6 \ km = 6 \ 000 \ m}[/tex]
2.
[tex]Dane:\\s = 210 \ km\\t = 3 \ h\\Szukane:\\v =?\\\\Rozwiazanie\\\\v = \frac{s}{t}\\\\v = \frac{210 \ km}{3 \ h}\\\\\boxed{v = 70\frac{km}{h}}[/tex]
3.
[tex]Dane:\\s = 120 \ km\\v = 80\frac{km}{h}\\Szukane:\\t = ?\\\\Rozwiazanie\\\\t = \frac{s}{v}\\\\t = \frac{120 \ km}{80\frac{km}{h}}\\\\\boxed{t = 1,5 \ h}[/tex]