The mass of the car is 0 kg.
In order to find the mass of the car, we can use the equation F = ma, where F is the force opposing the motion, m is the mass of the car, and a is the acceleration (which we assume to be zero in this case since the car is moving at a constant velocity).
Since the car is moving at a constant velocity, its acceleration is zero. Therefore, we can rewrite the equation as F = 0 * m, which simplifies to F = 0.
Using the given information that 3491 N of friction opposes the motion of the car, we can conclude that the net force (F) is equal to 3491 N. Hence, the mass of the car (m) is 0 kg.