Two small blocks, each of mass $m,$ are connected by a string of constant length $4h$ and negligible mass. Block A is placed on a smooth $($frictionless$)$ tabletop as shown below, and block B hangs over the edge of the table. The tabletop is a distance $2h$ above the floor. Block B is then released from rest at a distance $h$ above the floor at time $t=0.$ Express all algebraic answers in terms of $h,m,$ and $g.$

a$.$ Determine the acceleration of block B as it descends. $(2$ marks$)$

b$.$ Block B strikes the floor and does not bounce. Determine the time at which block B strikes the floor. $(2$ marks$)$

c$.$ Determine the distance between the landing points of the two blocks. $(4$ marks$)$