Question

Find the geopotential height of an aircraft flying sea level where L0=-0.0065 k/m, p=30070.36Pa.

(a) 9120 km

(b) 9144 km

(c) 9854 km

(d) 9874 km

This question was addressed to me during an internship interview.

I'm obligated to ask this question of Measurement of Height in section Atmosphere and Air Data Measurement of Aircraft Performance

Answer 1

Correct choice is (b) 9144 km

For explanation I would say: The answer is 9144 km. Given L0=-0.0065 k/m, p=30070.36 Pa.

We know T0=288.15K, p0=101325Pa, R=287 J/kg-K, g0=9.81m/s^2.

From H=\(\frac{T_0}{l_0}\)[\((\frac{p}{p_0})^\frac{-L_0R}{g_0}\)-1]

H=\(\frac{288.15}{-0.0065}\)[\((\frac{30070.36}{101325})^\frac{-(-0.0065)*287}{9.81}\)-1]

H=9144 km.