A box rests on top of a flat bed truck. The box has a mass of m = 18.0 kg. The coefficient of static friction between the box and truck is ?s = 0.82 and the coefficient of kinetic friction between the box and truck is ?k = 0.67. The truck accelerates from rest to vf = 15.0 m/s in t = 14.0 s (which is slow enough that the box will not slide).
In the previous situation, what is the frictional force the truck exerts on the box (in N)?