What is the pressure inside a system when the system-side column in an open mercury manometer is 75.0 mm lower than the atmosphere side when the atmospheric pressure is 735 mm hg?

Pressure can be measured using a U-tube manometer by measuring the difference of the height readings. The equation is equal to:

ΔP = ρgΔh

where

ΔP is the difference of pressure between gauge and atmospheric

ρ is the fluid used in manometer which is mercury (13,560 kg/m³)

g is 9.81 m/s²

Δh is the difference in height readings

The conversions is 101325 Pa = 760 mmHg

P - 760 mmHg = (13,560 kg/m³) * (9.81 m/s²) * (75 mm) * (1 m/1000 mm) * (760 mmHg/101325 Pa)

P = 834.83 mmHg