The given system of water, mercury, and methylated spirit is shown as follows :
Height of the spirit column, h1 = 12.5 cm = 0.125m
Height of the water column, h2 = 10 cm = 0.1 m
P0 = Atmospheric pressure
ρ1 = Density of spirit
ρ2 = Density of water
Pressure at point B = P0 + h1ρ1g
Pressure at point D = P0 + h2ρ2g
Pressure at points B and D is the same.
P0 + h1ρ1g = h2ρ2g
\(= \frac{ρ_1 }{ ρ_2} = \frac{h_2 }{ h_1} \)
\(=\frac{ 10 }{ 12.5 }= 0.8\)
Therefore, the specific gravity of spirit is 0.8.
Two vessels A and B are of the same size and are at the same temperature. A contains 1 g of hydrogen and B contains 1 g of oxygen. \(P_A\) and \(P_B\) are the pressures of the gases in A and B respectively, then \(\frac{P_A}{P_B}\) is:
In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy. The principle is named after Daniel Bernoulli who published it in his book Hydrodynamica in 1738.