Two blocks with masses $\backslash ($ M$\_\{1\}=2\mathrm{.}0\backslash$mathrm$\{$~kg$\}\backslash )$ and $\backslash ($ M$\_\{2\}=4\mathrm{.}0\backslash$mathrm$\{$~kg$\}\backslash )$ are hanged by an inelastic string that passes over a pulley $($which is attached to the ceiling$).$ The pulley is a solid disk with mass $\backslash ($ m$=1\mathrm{.}0\backslash$mathrm$\{$~kg$\}\backslash )$ and radius $25$ cm $.$ There is no friction at the rotational axis, but the surface of the pulley is rough. As the blocks and the string move, the string moves without slipping on the pulley.

$($a$)$ Draw the free$-$body diagrams for the block $1,$ block $2,$ and the pulley.

$($b$)$ Find the acceleration $($magnitude and direction$)$ of block $2.$