$7.$ Let $\backslash ($ v$($t$)\backslash )$ be the velocity of a ball dropped from the top of a building $($so the initial velocity of the ball is $0$ meters per second$).$ The ball's mass is $0\mathrm{.}2$ kilograms. The force of air resistance is proportional to the velocity and is given by $\backslash ($ F$\_\{$R$\}=-0\mathrm{.}008$ v $\backslash ).$ Set up a differential equation for $\backslash ($ v$($t$)\backslash )$ using Newton's Law of motion. What velocity does the rock approach as time $\backslash ($ t $\backslash )$ gets large?