Question

A lake contains water at a maximum depth of 237.3 meters. This water has a density of 989 kg/m3 and the acceleration due to gravity at this location is 9.806 m/s2. The air above the water has a barometric pressure of 29.83 in of Hg where the altitude correct for pressure is -1.87 in of Hg to get absolute pressure. What is the absolute pressure at the bottom of the lake?

Answer 1

Answer:690.21 mm of Hg

Step-by-step explanation:

Given data

depth of lake
`\left (h\right )`=237.3m

density of lake water
`\left ( \rho\right )`=
`989kg/m^3`

acceleration due to gravity
`\left ( g\right )`=
`9.806m/s^2`

air above water has a barometric pressure of 29.83in of Hg=711.2 mm of Hg

Altitude correct for pressure=1.87in of Hg=47.5 mm of Hg

Absolute pressure above water =711.2-47.5mm of Hg=663.7 mm of Hg

Absolute pressure at bottom of Lake=Pressure at surface level +
`\left ( \rho * g* h\right )`

Absolute pressure at bottom of Lake=663.7+
`(989* 9.81\273.3)/(10^(5))`

Absolute pressure at bottom of Lake=690.21 mm of Hg