An object is dropped into a large reservoir containing a viscous fluid such that it strikes the fluid surface with a velocity of $16\mathrm{.}5$ m$/$s$.$ Within the fluid, the object decelerates according to the relation a$($v$)=0\mathrm{.}8$v $+10$ m$/$s$2,$ where v $($in m$/$s$)$ is the object$$s velocity. Given that the object takes $3$ seconds to reach the bottom of the reservoir, determine: $($i$)$ The velocity of the object when it reaches the bottom of the reservoir. $($ii$)$ The depth of the reservoir.