The van seen from the rear is traveling at a speed v around a turn of mean radius r bank...

The van seen from the rear is traveling at a speed v around a turn of mean radius r banked inward at an angle θ. The effective coefficient of friction between the tires and the road is μ. Determine (a) the proper bank angle for a given v to eliminate any tendency to slip or tip, and (b) the maximum speed v before the van tips or slips for a given θ. Note that the forces and the acceleration lie in the plane of the figure so that the problem may be treated as one of plane motion even though the velocity is normal to this plane.