Odpowiedź :
[tex]Dane:\\s_1 = 240 \ m\\s_2 = 3 \ km = 3 \ 000 \ m\\v = 54\frac{km}{h} = 54\cdot\frac{1000 \ m}{3600 \ s} = 15\frac{m}{s}\\Szukane:\\t = ?\\\\Rozwiazanie\\\\v = \frac{s}{t} \ \ \rightarrow \ \ t = \frac{s}{v}\\\\s = s_1+s_2 = 240 \ m = 3000 \ m = 3 \ 240 \ m\\\\t = \frac{3240 \ m}{15\frac{m}{s}}\\\\\boxed{t= 216 \ s = 3 \ min \ \ i \ \ 36 \ s}[/tex]