Question #2e732

1 Answer
Mar 11, 2017

The building's height h=200m.
So the barometer reading at lower floor is higher than the upper floor due to the pressure exerted by 200m air column.

Pressure exerted by the air column
=h×d×g
Where d=density of air and g = acceleration due to gravity

The barometer reading difference gives the pressure difference of 7674.15=1.85cm=1.85×102m of Hg column.

Here the barometric pressure difference is equal to the pressure of 200m air column.

Let the density of air be dkg/m3

So

200×d×g=(7674.15)×102×13600×g

d=1.85×102×13600200kg/m3

=1.285 kg/m3