1. The problem statement, all variables and given/known data 2. Relevant equations F = ma 3. The attempt at a solution I already have the solution, however, I have a few questions. 1)In the solution they have taken m2's acceleration relative to the ground to be a0-a downwards. However, if a>a0, then wouldn't the acceleration relative to the ground end up being being upwards? In that case, how is assuming the acceleration downwards and being equal to a0-a correct? 2) If viewed from the accelerating frame of the movable pulley, pseudo force upwards = m2a0 therefore, the eq of motion for m2: T-m2g+m2a0 = m2a => T-m2g = m2(a-a0) Why does the pseudo force method lead to an answer that is "biased" towards m2 accelerating upwards relative to the ground? i.e assuming m2 will be accelerating upwards from the ground frame?