Total pressure head in a pipe

[Deathfish]

Homework Statement

In a water treatment plant, a 30cm pipe carries raw water at a rate of 6m³/min. The pressure at a given point is 3.5 bar. If that point is 10m above the datum line, calculate the total head at that point in a) m of water b) m of Hg

Homework Equations

Z + $$\frac{P}{\rho g}$$+$$\frac{v^2}{2g}$$

The Attempt at a Solution

Ok i got 10 + $$\frac{350000}{9810}$$+$$\frac{1.41^2}{2x9.81}$$ = 45.78m H2O then I divided by 13.6 to get 3.37 m Hg

Question is how do i find m of Hg by directly modifying the formula instead of calculating head of water first?

ok what i mean is how to convert easily between head of oil, head of mercury, head of alcohol etc etc

 

[Valkarie]

.You can't convert "easily" between the different heads, since they each depend on the density of the fluid and gravity. You will need to use the equation for each type of head you want to calculate.For example, to calculate the head in metres of mercury, you would use the equation:Z + \frac{P}{\rho_Hg g}+\frac{v^2}{2g}where Z is the elevation in metres, P is the pressure in pascals, ρHg is the density of mercury (13,595 kg/m3), g is the acceleration due to gravity (9.81 m/s2) and v is the velocity of the fluid in m/s.