AIDEZ-MOI S.V.P !!!!!!!!!!!!!!!

1/
1 km = 1000 metres   1 h = 3600 secondes
27000/3600 = 7.5
donc 27 km/h = 7.5 m/s

2/  1 m = 0.01 km
donc 10ms
0.01 x 3600 = 36
10m/s = 36 km/h

3/ 0.95 km /mn
1 h = 60 mn
0.95 *60 = 57
0.95 km/mn = 57 km/h

4/
1.5 km/mn =   m/s
1.5 km = 1500 metres
1mn =60secondes
1500/60 =25

1.5km/mn = 25 m/s