Resposta:
4,285km
Explicação:
10km = 10.000m
70km/h = 19,4444 m/s
30km/h = 8,3333 m/s
t = d/v
10.000/19,4444 = 514,286 s
d = 8,3333 * 514,286 = 4.285,70 m = 4,285km
####### ou ######
t = d/v
t = 10/70 = 0,14285h
d = v * t
d = 30*0,14285 = 4,285km
####### ou ######
70 = 10
30 = X
30*10=70x
x = 300/70 = 4,285km
