Question

The gage pressure in a liquid at a depth of 3 m is read to be 28 kPa. Determine
the gage pressure in the same liquid at a depth of 9 m.

Answer 1

Explanation:

145 kPa

Question: The absolute pressure in water at a depth of 5m is read to be 145 kPa.

Answer 2

Assumptions The variation of the density of the liquid with depth is negligible.

Analysis The gage pressure at two different depths of a liquid can be expressed as

P₁ = pgh and P₂ = pgh₂

Taking their ratio,

= h₂ P pgh h₁

Solving for P, and substituting gives

P₂ h₂ 9 m h₁ 3 m = (28 kPa) 84 kPa

1

Discussion Note that the gage pressure in a given fluid is proportional to depth.