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.
Find the mean deviation about the mean for the data 38, 70, 48, 40, 42, 55, 63, 46, 54, 44.
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.
