1. The problem statement, all variables and given/known data So there are 2 boxes: 1 has a mass of 16kg and the other is 88kg. There is friction between 2 boxes, the surface which box 88kg is on is frictionless. Static friction coefficient is 0.38. Box 16kg is not on the surface, it's is push against the 88kg box. What is the minimum pushing force required in order for box 16kg not drop 2. Relevant equations F=ma 3. The attempt at a solution So I do F=ma in the y direction which is Fs - mg=0 to find Fs. Then I do in the x direction F-Fn= 0. From Fs I can get Fn by dividing Fs by 0.38. Did I solve the problem right ?