The pilot of an airplane reads the altitude 9,000 m and an absolute pressure of

Question

The pilot of an airplane reads the altitude 9,000 m and an absolute pressure of 25 kPa when flying over a city. Calculate the local atmospheric pressure in that city in kPa and in mm Hg. Take the density of air and mercury to be 1.15 kg/m3 and 13,600 kg/m3. respectively. (20) The average temperature of the atmosphere in the world is approximated as a function of altitude by the relation: Tatm = 288.15 - 6.5z Where Talra is the temperature of the atmosphere in K and z is the altitude in km with z = 0 at sea level. Determine the average temperature of the atmosphere outside an airplane that is cruising at an altitude of 12,000 m. Determine the density of air at 12 km if the pressure is known to be 1.8506 x 104 N/m2. (20)

Explanation / Answer

1) Local atmospheric pressure = Absolute Pressure + *g*H

= 25 kPa + 1.15*9.8*9000/1000 kPa

= 25 + 101.43

= 126.43 kPa

P = mercury * g*H

126430 = 13600 * 9.8 * H

H = 0.9486 m = 948.6 mm Hg

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.