1. The problem statement, all variables and given/known data If I act a force on a system consisting of a heavy and light body in contact with each other from the side of the heavy body and then I act the same force from the side of the light body, the inertial force between the two bodies would be the same? 2. Relevant equations 3. The attempt at a solution I know from experience that the inertial force is bigger in the first case Does friction has to do with the proof?