Answer:
7 hours
Explanation:
Lets call the velocity of car one V1 and the velocity of car 2 V2
V1 = 57mph and V2 = 66mph
Find the change in velocity
66mph - 57mph = 9mph
This means that Car 2 will be getting 9 miles farther away from car 1 every hour.
x/v = t where x is the miles apart
63m/9mph = 7hours
I hope this makes sense.