The flow about a 150 mm artillery projectile which travels at 600 m/s through still air at 30°C and absolute pressure 101.4 kPa is to be modeled in a high-speed wind tunnel with a 1:6 model. If the wind tunnel air has a temperature of −18°C and absolute pressure of 68.9 kPa, what velocity is required? If the drag force on the model is 35 N, what is the drag force on the prototype if skin friction may be neglected?
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