1. The problem statement, all variables and given/known data Two boxes have masses m1 and m2, and m2 is greater than m1. The boxes are being pushed across a frictionless horizontal surface. As the drawing shows, there are two possible arrangements, and the pushing force is the same in each. In which arrangement, (a) or (b), does the force that the left box applies to the right bo have greater magnitude, or (c) is the magnitude the same in both cases? 2. Relevant equations F=ma 3. The attempt at a solution I can't see why the answer isn't (c) here. If the pushing force is the same in both cases and the area of contact is the same between the boxes. Can someone explain why it's different please?