1.2m/s=1.2×3600m/(1×3600s)=4320m/h=[4.32]km/h
2.5m/s=2.5×3600m/(1×3600s)=9000m/h=[ 9 ]km/h
30m/s=30×3600m/(1×3600s)=108000m/h=[108]km/s
700ms=700×3600m/(1×3600s)=2520000m/h=[2520]km/h