1. The problem statement, all variables and given/known data The coefficient of static friction is 0.621 between the two blocks shown. The coefficient of kinetic friction between the lower block and the floor is 0.129. Force F causes both blocks to cross a distance of 5.10 m, starting from rest. What is the least amount of time in which the motion can be completed without the top block sliding on the lower block, if the mass of the lower block is 1.05 kg and the mass of the upper block is 2.91 kg? __ |__|-->F |_____| 2. Relevant equations 3. The attempt at a solution i really have no idea how to start this problem. so i know that both the static friction between the upper and lower block will act to the left and the kinetic friction between the lower block and the floor will act to the left. I think what i ultimately need to find the the maximum acceleration the system can have right before the block slips. This acceleration can be used to find the time, using kinematic equations. So for the whole system: Fnet = (ml +mu)a = Fext - Ffs - Ffk I also know that the upper block will slip when the force of static friction is at its max so: Ffs.max = uFn = (0.621)(2.91)(9.8) = 17.7 N Im just not sure where to go from here... THANKS!!