1 km = 1000 m
1 h = 3600 s
3.6 km/h = 3600 m / (3600 s) = 1 m/s
Thus,
70 m/s = (70 / 1000) km / ((1 / 3600) h) = (70 * 3600 / 1000) km/h =
70 * 3.6 km/h = 252 km/h.
The car travelling at 252 km/h for 6.5 h will cover a distance d:
d = 252 km/h * 6.5 h =
1638 km.