Consider a bus of mass three megagrams having its center of mass at G moving along a banked road at a constant speed. The coefficient of static friction between the tires and the road is 0.5. What is the maximum angle of the banked road where the bus would not slip or tip? Drawing the free-body diagram, gravitational, frictional, and normal forces are denoted. The frictional forces at two contacts are expressed, and the weight of the bus is resolved into its components. Consider the condition for no slipping. Since the bus travels with constant speed, it satisfies the equilibrium conditions, and the resultant forces acting on it in both directions are zero. Solving the two equations gives the maximum angle for no slipping. When the bus starts tipping, it loses contact with the upper point, and no reaction or frictional force acts at the upper point. To prevent tipping, the resultant moment about the lower point must be zero. Solving the equation gives the maximum angle for no tipping.