Determine the factor the drag of the model needs to be multiplied by under each condition to give the drag of the full scale submarine.

A 1:50-scale model of a submarine is to be tested in a towing tank under two conditions: motion at the free surface and motion far below the surface. The tests are performed in freshwater. On the surface, the submarine cruises at 24 knots. Determine the speed the model should be towed to ensure dynamic similarity. The sub cruises at 0.35 knot below the surface. Determine the speed should the model should be towed to ensure dynamic similarity under the surface. Determine the factor the drag of the model needs to be multiplied by under each condition to give the drag of the full scale submarine.