Consider a submarine cruising at 0.18 m/s far below the surface in sea water at 20 degree C. A 1:50-scale model of the submarine is to be tested in a towing tank. The tests are performed in fresh water at 20 degree C. At what speed should the model be towed to ensure dynamic similarity? What must the drag of the model be multiplied by to give teh drag of the full-scale submarine?