$3.)(15$ pts $)$ Find the arc length of the vector function $r(t)=($:$t,4t^{\frac{3}{2}},2t^{\frac{3}{2}}$:$)$ over the interval $0,3.$

$3.)(15$ pts $)$ Find the arc length of the vector function $r(t)=($:$t,4t^{\frac{3}{2}},2t^{\frac{3}{2}}$:$)$ over the interval $0,3.$