A pilot records the atmospheric pressure outside its plane as 63cm of Hg while a ground observer records a reading of 75cm of Hg for the atmospheric pressure on the ground. Assuming that the density of the atmosphere is constant, calculate the height of the plane above the ground. (Relative density of Hg = 13.0 and that of air = 0.00013)
-
1200m
- 6300m
- 7500m
- 13800m
The correct answer is: A
Explanation
Difference in pressure = 75 - 63= 12cmHg
pressure = hge
difference in height = \(\frac{12}{10 \times \frac{0.00013}{13}}\)
= 1200m