Simple Mercury Barometer - Example 1

Converting the Unit from cmHg to Pa

Pressure in unit cmHg can be converted to Pa by using the formula

P = hρg

Example 1:

Find the pressure at point A, B, C, D, D, E and F in the unit of cmHg and Pa. [Density of mercury = 13600 kg/m³]

Answer:

Pressure in unit cmHg	Pressure in unit Pa
PA = 0 PB = 17 cmHg PC = 17 + 59 = 76 cmHg PD = 76 + 8 = 84 cmHg PE = 76 cmHg PF = 76 cmHg	PA = 0 PB = hρg = (0.17)(13600)(10) = 23,120 Pa PC = hρg = (0.76)(13600)(10) = 103,360 Pa PD = hρg = (0.84)(13600)(10) = 114,240 Pa PE = hρg = (0.76)(13600)(10) = 103,360 Pa PF = hρg = (0.76)(13600)(10) = 103,360 Pa