A 5 kg block 'A' on a rough plane (angle of inclination=30) is connected to a massiess string which passes over a frictionless pulley at the top of the plane ;and is connected to a 4 kg black 'B' which hangs vertically. If the coefficient of kinetic friction between 'A' and plane is 0.25, find the acceleration of the system when released , and the tension the string.