# What will be the gauge pressure and the absolute pressure of water at depth 12m below the surface?

##### 1 Answer
Aug 9, 2015

(a). $117 \text{kPa}$

(b). $217 \text{kPa}$

#### Explanation:

Absolute pressure = gauge pressure + atmospheric pressure.

"Gauge Pressure" is the pressure due the liquid alone. This is given by:

$\text{GP} = \rho g h$

= ${10}^{3} \times 9.8 \times 12 = 1.17 \times {10}^{5} N . {m}^{- 2}$

$= 117 \text{kPa}$

To get the absolute pressure we need to add on the pressure due to the weight of the air above it. We add on the atmospheric pressure which I will assume to be $100 \text{kPa}$

Absolute pressure $= 117 + 100 = 217 \text{kPa}$