1200cm/s =12 m/s=12 *(1/1000)km / (1/3600)h= 12*3.6 km/h=43.2 km/h
1200cm/s=1200*(0.01m)/s=12m/s1km/h=1000m/3600s=1/3.6 m/s1m/s=3.6km/h1200cm/s=12m/s=12*3.6m/s=43.2m/s