f the absolute pressure in a tank is 128 kPa, determine the pressure head in mm of mercury. The atmospheric pressure is 100 kPa. The density of the mercury is 13,550 kg/m3. Express your answer using three significant figures.

211 mmHg

Explanation:

Absolute Pressure = Gauge Pressure + Atmospheric pressure

128 = Gauge Pressure + 100

Gauge Pressure = 28 KPa = 28 * 10³ Pa

Also Gauge Pressure = ρgh

ρ = density = 13550 kg/m³

g = acceleration due to gravity = 9.8 m/s²

h = pressure head = ?

28 * 10³ = 13550 * 9.8 * h

h = 28000 / (13550 * 9.8)

h = 0.211 m = 211 mm