1. The problem statement, all variables and given/known data http://i.imgur.com/0gexJ.png 2. Relevant equations F=kx (Hooke's Law), ƩFy=0 3. The attempt at a solution I drew a free-body diagram for each block. For block A, I get the equilibrium equation: Fa = (10kg)(9.81ms^-2) = 98.1N = kx_a x_a = 300mm-250mm = 50mm k = 1.962kN/m For block B I get the equilibrium equation of Fb = 98.1 - Wa = kx_b but it seems as I don't need this equation. Is this correct, and if not, should I draw a "combined" FBD? If so, how? Thanks.