Calc question regarding rate of increasing distance.?

Question

Two cars start moving from the same point. One travels south at 44 mi/h and the other travels west at 33 mi/h. At what rate is the distance between the cars increasing four hours later?

Answer 1

v = √(33^2 + 44^2) = 55 mph

Unless one or both of the cars accelerate, this relative velocity remains constant, so 4 hours later the relative velocity between both cars is 55 mph.

Answer 2

What you can do simply is to calculate say for 10 min. how much distance they hvae traversed.  Then repeat it for 5 min..etc..  The correlate accordingly.  Giving a basic answer.

Advanced is that they would have 10 miles/hr difference.  assuming they go uniform speed, it would be increasing 10 miles / for each hour......

First hour 10 miles,  second hr -add another 10 miles, third hr. add another 10 miles.

Answer would be 10 miles / hour is the rate of increasing gap of distance between the two.