A car is going around a circular banked road (the banking angle is15 degree). The coefficient of static friction among the rubber and the road is 0.7. The radius of this part of the road is 25m. Please give the recommended speed zone (i.e. give the minimum safe speed with no skidding towards the center of the circle, and the maximum safe speed without skidding off the road). Start with a free-body diagram of the car on the banked road.