An airplane flies at 20,000 ft, where the atmospheric pressure is 45kPa and the temperature is -24C. A pitot-static tube mounted on the plane in a the free-stream gives a differential manometer reading quivalent to 8.5 inches of H2O. A) Estimate the speed of the airplane, assuming incompressible flow. Assume air to be an ideal gas with gas constant of 287 J/kg.K.