The height at which the atmosphere ceases to exist is about 80km. If the atmospheric pressure on the ground level is 760mmHg, the pressure at a height of 20km above the ground level is
(ρm = 13.6g/cm\(^3\) ρ = 0.00013g/cm\(^3\) )
A
380mmHg
B
570mmHg
C
190mmHg
D
480mmHg
Verified Correct Answer: B.
Physical Principles & Numerical Solution
ρ\(_m\)h\(_m\) = ρ\(_a\)h\(_a\)
13.6(760 - p) \times 10\(^{-3}\) = 13 \times 10\(^{-5}\)(20 \times 10\(^3\))
760
-
p
=
13 \times 10\(^{-5}\) \times 20 \times 10\(^{3}\)
13.6 \times 10\(^{-3}\)
=
19.12
\times
10\(^{1}\)
760 - p = 191.2
p = 760 - 191.2 ≈ 570mmHg
Source: Myschool Past Questions Archive (Record #55825)