1. The problem statement, all variables and given/known data A 9 kg block on a frictionless table is connected by a light massless cord through a frictionless pulley to a 3 kg block hanging over the edge of the table. The blocks are free to accelerate. What is the tension in the cord? 2. Relevant equations sum of forces = F tension + F gravity + F normal = 0 The blocks are connected by massless string so we consider them as one object. F = ma 3. The attempt at a solution Since the blocks are not moving they are in static equilibrium. The net forces on the block unit = 0 I know I need to glean something from the fact that the blocks are free to accelerate but I am not sure what it is. Also, if the table is frictionless what is opposing the force of tension on the cord to keep it from sliding off the table. I know this is a basic problem but I can not work it! If someone could please push me in the right direction I would appreciate it very much.