A particle A of mass 2kg lies on the edge of a table of height 1m. It is connected by a light inelastic string of length 0.7m to a second particle B of mass 3 kg which is lying on table 0.25m from the edge. If A is pushed gently so that it starts falling from table then, find the speed of B when it starts to move. Also find the impulsive tension in the string at that moment.