Case - I
Acceleration in A object, a1=25m1
Acceleration in B object, a2=25m2
∴a1a2=25m125m2=m2m1=43
Case - II
Acceleration in A object, A1=30m1
Acceleration in B object, A2=30m2
∴a1a2=25m125m2=m2m1=43
∴ The difference in new and earlier acceleration
43−43=0