Hello there. I need some help in solving the following problem: Problem: A race-car driver is driving her car at a record-breaking speed of 225 km/h. The first turn on the course is banked at 15 degree, and the car's mass is 1450 kg. a) Calculate the radius of curvature for this turn. b) Calculate the centripetal acceleration of the car. c) If the car maintains a circular track around the curve (does not move up or down the bank), what is the magnitude of the force of static friction? d) What is the coefficient of static friction necessary to ensure the safety of this turn? I'm not sure if my answers are correct, since I assume I don't need to take into account the friction forces to calculate a) and b). For a), I used the formula: r = v^2/(g.tan A). The result is 1487.584 km. For b), a = (v^2)/r = 2.626 m/s^2. Now.. I'm stuck in c). From common sense, the force of static friction will be 0 since I am assuming there is no friction to calculate A and B. That unless my assumption is wrong. Any help to solve this problem is greatly appreciated!