A jet airplane in level flight has a mass of 8.67×104 kg, and the two wings have an estimated total area of 95.0 m2. (a) What is the pressure difference between the lower and upper surfaces of the wings? Pa (b) If the speed of air under the wings is 235 m/s, what is the speed of the air over the wings? Assume air has a density of 1.29 kg/m3. m/s (c) Explain why all aircraft have a "ceiling," a maximum operational altitude.