The acceleration of car A directly affects its speed. As the car accelerates at a rate of 4.0 m/s^2, its speed will increase by 4.0 meters per second every second.
The speed of car B when it passes car A depends on the initial speed of car B and the distance between the two cars. However, since car B is passing car A, it must have a higher speed than car A at that moment.
It is possible for car A to catch up to car B if the acceleration of car A is greater than the initial speed of car B. However, if the acceleration of car A is constant at 4.0 m/s^2, car A will never catch up to car B as car B will continue to accelerate at a higher rate.
Using the formula v = u + at, we can calculate that it will take car A 5 seconds to reach a speed of 20 m/s (assuming it starts from rest and maintains a constant acceleration of 4.0 m/s^2).
Other factors that may affect the acceleration and speed of the two cars include the mass and aerodynamics of the cars, the surface and conditions of the road, and any external forces such as wind or friction. Additionally, the skill of the drivers and their reaction times may also impact the acceleration and speed of the cars.