The Daytona International Speedway in Daytona Beach, Florida is famous for its races, especially the Daytona 500, held every spring. Both of its courses features four-story, 20 degrees banked curves with friction and maximum "R", which is unknown. If a car negotiates the curve too slowly, it tends to slip down the inclined of the turn. Whereas if it's going too fast, it may begin to slide up the incline. Assume weight of the car is 784.4 kg and coefficient of static friction is 0.25.
What is the maximum radius of the above race track if the maximum speed of the car that can travel safely around the above racetrack is 44 meters per second?