Jawabanmu

2014-08-29T08:21:57+07:00
72 km/jam = 72000/3600
                = 20 m/s
2014-08-29T09:07:51+07:00
72 km=72 x 1000 =72000
1 jam= 1 x 3600
jawabannya : 72000/3600