need to know mass and acceleration of a 30.5 bloch connected to an empty 1.00kg bucket by cord running over a frictionless pulley coefficient of static friction between table and block is 0.405 and coeff. of kinetic frict. between the table and the block is 0.320 adding sand gradually until the system just begins to move. how to calc mass of sand added and acceleration of the system

The bucket starts moving when

(Mbucket +Msand)g = 0.405 Mblock*g
g's cancel. Solve for Msand

After that,
a = g[(Msand +Mbucket - 0.320 Mblock]/(Msand + Mblock + Mbucket)