Final answer:
To find the acceleration of the car, subtract the force of friction from the force applied by the engine. Use Newton's second law of motion to solve for the acceleration.
Step-by-step explanation:
To find the acceleration of the car, we need to determine the net force acting on it. The net force can be calculated by subtracting the force of friction from the force applied by the engine. The force of friction can be found using the equation: force of friction = coefficient of friction × normal force.
The normal force can be calculated by multiplying the mass of the car by the acceleration due to gravity. Once we have the force of friction, we can subtract it from the force applied by the engine to find the net force. Finally, we can use Newton's second law of motion, which states that the net force is equal to mass times acceleration, to solve for the acceleration.
In this case, the force of friction is 0.45 × (900 kg × 9.8 m/s²) = 3969 N. The net force is 4000 N - 3969 N = 31 N. Plugging in the mass of the car (900 kg) and the net force (31 N) into the equation F = ma, we can solve for the acceleration: a = F/m = 31 N / 900 kg = 0.0344 m/s².