Question

To save money on buying mercury you build a BAROMETER using water as the fluid inside the column. Approximately, how tall is your barometer? (HINTS r(mercury) =1.36 x 10^4 kg/m^3 and r(water) = 1.00 x 10^3 kg/m^3).

Answer 1

To solve this problem we need to use the concepts related to fluid density. Since we need to know a height point of two different liquids, their pressures must be equal, so

`P_1 = P_2`

`\rho_1 gh_1 = \rho_2gh_2`

Where,

`\rho =`Density

g = Gravitational acceleration

h = Height

Our values are given as,

`\rho_1 = 1.36*10^4kg/m^3`

`\rho_2 = 1*10^3kg/m^3`

`h = 76.02cm \rightarrow` Standard mercury pressure at 1atm, the barometer height is 760.2mm.

Replacing we have,

`1.36*10^4 *76.02= 10^3*h_2`

`h_2 = 1033.87cm`

Therefore the tall of the barometer would be 1033.87 (Inconvenient compared with the Mercury Barometer)