A top$-$loading washing machine has a cylindrical tub that rotates about a vertical axis. The tub of one such machine starts from rest and reaches an angular speed of $2\mathrm{.}0$ rev$/$s in $7\mathrm{.}0$ s$.$ The lid of the machine is then opened, which turns off the machine, and the tub slows to rest in $9\mathrm{.}0$ s$.$ Through how many revolutions does the tub turn during this $16$ s interval? Assume constant angular acceleration while it is starting and stopping