Figure shows two blocks A and B are connected through pulley and spring system. Block A, on a frictionless surface, has a mass of 2 Kg, Block B, suspended by cables, has a mass of 3 Kg. The spring has a stiffness of k = 500 N/m and an unstretched length of 400 mm. the system is released from rest in the position shown (x = 800 mm).The speed of the block A (rounded off to the nearest higher integer) in m/s when x = 0 mm is $\left[g=10m/s^2\right]$