(25 poitns) A highway is designed for traffic moving at 65 mph. Along a certain portion of the highway, the radius of a curve is 900 ft. The curved is banked, as shown below so that no friction is required to keep cars on the road. Determine, a. The required banking (0) of the road so that no friction is required. b. The minimum coefficient of friction between the tires and the road that would keep traffic from skidding at this speed if the curve is not banked