If block A is moving with an acceleration of 5 m s-2, the acceleration of B w.r.t ground is

By virtual work method:Acceleration of B w.r.t. A will be 10 ms-2 downward.Apart from this, B also has an acceleration 5  ms-2 in horizontaldirection along with A, so net acceleration of B is102+52=100+25=125=55ms−2