A 10 kg block rests on a 30° inclined plane. The block is attached to a bucket by an ideal pulley system depicted below. The mass in the bucket is gradually increased by the addition of sand. At some point, the bucket will accumulate enough sand to set the block in motion. The coefficients of static and kinetic friction are 0.60 and 0.50 respectively.

a) Determine the mass of sand in [kg], including the bucket, needed to start the block moving.

b) Use the mass found in the part a to determine the block's acceleration, in [m/s²] up the plane.