THE PROBLEM: A sports car is accelerating up a hill that rises 21.2 ° above the horizontal. The coefficient of static friction between the wheels and the road is μs = 0.880. It is the static frictional force that propels the car forward. (a) What is the magnitude of the maximum acceleration that the car can have? (b) What is the magnitude of the maximum acceleration if the car is being driven down the hill? I set up my fbd with the static frictional force acting in the -x direction, the normal force acting perpedicular to the inclined plane, and the weight acting in the -y direction. Without knowing the weight of the car or if it is at a constant velocity, I'm not sure how to go about setting up this problem.