1. The problem statement, all variables and given/known data it is Problem 3.30. 2. Relevant equations I am not sure how to sum the forces about each consecutive pulley I have been at this for 4 hours now. It is sad I can solve the DE questions and not this. 3. The attempt at a solution I had the first pulley at the top as (where y is dv/dt) -T+mg=my1 Then I figured if i did it with just one extra pulley I could model the rest how ever it is not correct. -2T+mg=-my2 (as i set the up direction to be negative and this mass would go up) Then with two pulleys with the string under it I had either -3T+mg=-ma or -4T+mg=-my2 What I don't get is how the tension from each consecutive pulley connected to the center of the one above it will effect the system.