Final answer:
The friction acting on the car is 2,000 N, calculated by subtracting the net force necessary for the car's acceleration from the total force provided by the engine.
Step-by-step explanation:
The question concerns determining the amount of friction acting on a car that is accelerated by a given force and has a known mass. Using Newton's second law, which states that the net force is equal to the mass times the acceleration, we can first calculate the net force required to produce the given acceleration. Afterward, we can determine the frictional force by subtracting this net force from the engine's provided force.
In the given problem, the car is accelerated at 9 m/s2 by an engine force of 20,000 N, and the car's mass is 2,000 kg. The net force needed for this acceleration is mass multiplied by acceleration: F_net = m × a = 2,000 kg × 9 m/s2 = 18,000 N. If the engine provides more force than is needed for acceleration, the remainder is counteracted by friction. So, the frictional force is the engine force minus the net force: Friction = F_engine - F_net = 20,000 N - 18,000 N = 2,000 N. Hence, the friction acting on the car is 2,000 N.