1. A package of mass m is dropped vertically onto a horizontal conveyor belt whose speed is v = 1.1 m/s, and the coefficient of kinetic friction between the package and the belt is μk = 0.60. For how much time does the package slide on the belt (until it is at rest relative to the belt)? 2. Sum of all the forces = ma 3. Free body diagram: The picture is the book answer. I drew a similar diagram except with Ff in the opposite direction. Why is Ffr in the direction of velocity for this problem? Compared to a problem where a child is on a slide, friction is on the opposite direction of the child's motion. I always thought that friction was suppose to be on the opposite direction of motion.