6. Include a Free-Body Diagram A car of mass 1.1 x 10^3 kg travels around a frictionless, banked curve of radius 85 m. The banking is at an angle of 19 to the horizontal, as shown in Figure 4. (a) What force provides the centripetal acceleration? (b) What constant speed must the car maintain to travel safely around the curve? (c) How does the required speed for a more massive vehicle such as a truck, compare with the speed required for this car