Răspuns :
Răspuns:
10x1000=10000m
10000m:20m=5000de sec
Explicație pas cu pas:
20m/s=20•3600m/h
20m/s=72000m/h
20m/s=72km/h
20m/s=10km/500s
20m/s=72000m/h
20m/s=72km/h
20m/s=10km/500s