A flatbed truck travels with a constant speed v = 28 m/s in a circle of radius R = 112 meters in a flat parking lot. A box which rests in the truck bed is held in place only by friction.(a) What is the centripetal acceleration of the box?(b) What is the minimum coefficient of static friction necessary to keep the box from sliding in the truck bed?[Use g = 10 m/s^2]