The Meteorological Service said the atmospheric pressure was 740 mm Hg. Art. Express it in SI units

The Meteorological Service said the atmospheric pressure was 740 mm Hg. Art. Express it in SI units. Which formula should you use?

In SI units, pressure is measured in pascals (Pa). To convert pressure from mm Hg. Art. in Pa we use the hydrostatic pressure formula:

p = ρ * g * h,

where ρ = 135.46 kg / m³ is the density of mercury;

g = 9.81 m / s² – acceleration of gravity at the Earth’s surface;

h is the height of the column of mercury, m.

Then the atmospheric pressure in SI is

p = 135.46 * 9.81 * 0.74 ≈ 983.36 Pa.