podana predkosc wyraz w kilometrach na godzine a)V= 15m/s b)V= 50m/s  

a) 15m/s= 15* (1/1000km)/(1/3600h)=15*36/10=54km/h b) 50m/s= 50* (1/1000km)/(1/3600h)=50*36/10=180km/h

a 54km/h b 180 km /h wyjasnienie Wiedzac, ze 1km = 1000m i 1h = 3600 s podstawiasz: A 15 m/s = 15 * (0.001)km / (1/3600)h = 0.015 km * 3600 * 1/h = 54 km/h.  B 50 m/s =15*(0.001)(1/3600) = 0.050*3600*1h=180km/h