Consider a wing in a high - speed wind tunnel. At a point on the wing, the velocity is 9 0 0 ft / s . The test section flow is at a velocity of 6 0 0 ft / s with a pressure and temperature of 1 atm and 5 0 5 R , respectively. If the test section flow velocity is reduced to 1 0 0 ft / s , what will the pressure coefficient become at the same point on the wing? The pressure coefficient after the change in velocity at that point is