1. The problem statement, all variables and given/known data Block B (1kg) is held in contact with block A (3kg). When block B is let go, A is pushed to the right with a force of 160N. Static friction is .50 between the 2 blocks. Block A pushes on B such that B is not touching the surface upon which A is moving on. It's held in the air with only the normal force from A supporting it. Find the force of friction on Block B, the normal force exerted by A on B, and vertical force exerted by B on A. 2. Relevant equations Newtonian forces of friction, gravity, etc 3. The attempt at a solution For the Normal force of A on B: to find a: Fnet = 160N = m(A+B)a --> a = 160/4 = 40m/s^2 mAa = F - F(BonA) FBonA = 160 - (3x40) = 40N = FAonB from Third Law For Force of Friction on B: Since friction would be working against gravity and there is no vertical motion, wouldn't the force of friction be mBg, its weight? The Max Ff would be Ff=μN = .50(40)=20N. Not sure about the vertical force of B on A.