Answer:
The value of pressure at an altitude of 10000 ft = 10 [tex]\frac{lb}{in^{2} }[/tex]
Step-by-step explanation:
Given data
Atmospheric pressure [tex]P_{0}[/tex] = 14.7 [tex]\frac{lb}{in^{2} }[/tex]
Pressure at 4000 ft = 12.6 [tex]\frac{lb}{in^{2} }[/tex]
If temperature is constant then the atmospheric pressure is varies with the altitude according to law
P (h) = [tex]P_{0}[/tex] [tex]e^{- kh}[/tex] ------ (1)
where k= constant & h = height
12.6 = 14.7 [tex]e^{- 4000k}[/tex]
0.857 = [tex]e^{- 4000k}[/tex]
㏑ 0.857 = - 4000 k
-0.154 = - 4000 k
k = 3.85 × [tex]10^{-5}[/tex]
Thus the atmospheric pressure at an altitude of 10,000 ft is
[tex]P_{10000} =[/tex] 14.7 × [tex]e^{- kh}[/tex] ----- (2)
Product of k & h is
k h = 3.85 × [tex]10^{-5}[/tex] × 10000
k h = 0.385
Put his value of k h = 0.385 in equation (2) we get
[tex]P_{10000} =[/tex] 14.7 × [tex]e^{-0.385 }[/tex]
[tex]P_{10000} =[/tex] 10 [tex]\frac{lb}{in^{2} }[/tex]
This is the value of pressure at an altitude of 10000 ft.