Final answer:
The car's acceleration cannot be determined without the time taken. More information is needed to determine the direction and additional forces acting on the car.
Step-by-step explanation:
The car's acceleration can be determined using the formula:
Acceleration = Change in velocity / Time
In this case, the car's initial velocity is 0 m/s and its final velocity is 42 m/s. The time taken is not provided, so we cannot calculate the car's acceleration given the given information.
Regarding the direction and additional forces acting on the car, the question does not provide any information. To determine the direction and additional forces, we would need more contextual information.