A wind-tunnel experimentis performed on a 1/25scale model of a supersonic aircraft. The prototype aircraft flies at 450 m/s in conditions where the speed of sound is 250 m/s and the air density is 0.89kg/m3. The model aircraft is tested in a wind tunnel in which the speed of sound is 280m/s and the air density is 0.56kg/m3. The drag force on the model is 100N. What speed must the flow in the wind tunnel be for dynamic similitude, and what is the drag force on the prototype?