1. The problem statement, all variables and given/known data Ok, so I know how to solve ALL the other types of newton problems that have been thrown at us. I can't understand conceptually when two masses are stacked on each other..I've tried to google it relentlessly and am going into my prof's office hours. The surfaces between the 10kg block and 20kg incline are frictionless. What is the force that has to be exerted on the incline so the 10kg block does not move up or down (aka is in equilibrium). The force is directed so that the incline is pushed to the left. The problem is attached... I've tried making free-body diagrams but to no avail - I just don't understand what forces exist in the free body diagrams! Is the force applied to the incline in two components relative to the block? I'm just so confused... 2. Relevant equations Newton's third law 3. The attempt at a solution Eh...many pages of useless scribble..