Question

The basic barometer can be used to measure the height of a building. If the barometric readings at the top and the bottom of a buikding are 730 and 755 mmHg, respectively, determine the height of the building. Assume an average air density of 1.25 kg/m^3. Provide with a simple sketch and graph it (hydrostatic pressure).

Answer 1

Answer:

$h = 269.6 m$

Explanation:

Pressure at the bottom of the building and at the top of the building must be related as

$P_{top} = P_{bottom} - \rho g h$

$P_{top} = 730 mm Hg$

$P_{bottom} = 755 mm Hg$

now we will have

$(755 \times 10^{-3})(13.6 \times 10^3)(9.81) = P_{bottom}$

$P_{bottom} = 1.007 \times 10^5 Pa$

$P_{top} = (730\times 10^{-3})(13.6 \times 10^3)(9.81)$

$P_{top} = 0.974 \times 10^5$

now we have

$(1.007 - 0.974)\times 10^5 = 1.25 (9.81) h$

$h = 269.6 m$