$(18$ points$)$ A research group is helping to design a submarine. The length of the prototype submarine is $5$ m $,$ and the design velocity, when fully submerged in water, is $0\mathrm{.}9\frac{m}{s}.$ The research group is going to build a $1$:$6$ scale model to test in their lab's wind tunnel. The measured drag on the model submarine is $11$ N $.$ Note that the shield surrounds the drag balance strut so that the aerodynamic draft of the strut itself doesn't influence the lab$-$measured drag. Use the fluid properties that are on your property and equation sheet.

Assuming that the submarine length is the "length" scale, what is the prototype Reynolds Number?

What air velocity in the wind tunnel is required to ensure dynamic similarity?

What is the drag force on the prototype submarine?