A block 'A' of mass 'm' is attached at one end of a light spring and the other end of the spring is connected to another block 'B' of mass 2 m through a light string as shown in the figure.'A' is held and B is in static equilibrium. Now A is released. The acceleration of A just after that instant is 'a'. In the next case, B is held and A is in static equilibrium. Now when,B is released, its acceleration immediately after the release is 'b'. The value of a/b is: (Pulley, string and the spring are massless)
For first case tension in spring will be
2mg-mg = ma
In second case