Car A is passing Car B as they come out of the tunnel. If Car A is traveling at 60 and Car B is traveling at 40, and they emerge side by side, then Car A will pass Car B because it is moving at a faster speed. Since Car B has greater acceleration it will eventually catch and pass Car A, but not until farther down the road. However, as they emerge from the tunnel, Car A will pass Car B.

I reason that car A would pass car B as the two leave the tunnel. I believe this to be so since car B would have to accelerate up to the speed of car A just to keep up with it. Once that is accomplished then car B would be capable of passing car A. The question , though, doesn't concern the events after the two are out the tunnel for some time. Car A is traveling much faster as the two leave the tunnel so therefore I conclude that this is the car that will pass the other.

Car A is passing Car b as they come out of the tunnel since Car A has a greater speed. After a minute, Car B and Car A will have the same speed, but it will take Car B a few minutes to catch up to car A. Car B will eventually pass Car A since it has a greater acceleration.