Astudent team is to design a human-powered submarine for a design competition. the overall length of the prototype submarine is 4.85 m, and its student designers hope that it can travel fully submerged through water at 0.44 m/s. the water is at t = 15c. the design team builds a one-fifth scale model to test in their university wind tunnel. a shield surrounds the drag balance strut that the aerodynamic drag of the strut itself does not influence the measured drag. the air is 25c and at one standard atmosphere pressure.

at what air speed do they need to run the wind tunnel in order to achieve similarity?