Question

As a swimmer goes from the surface of water to a depth of 20m, the change in the pressure on his body is nearly:

• A. 3 atmospheres
• B. 1 atmosphere
• C. 2 atmospheres
• D. zero

Answer 1

The correct option is C 2 atmospheres

$1atm={10}^{5}Pa$
Height of water column required to equal 1 atm is: $\zeta gh={10}^5$
$1000\times 10\times h={10}^5$
$h=10m$
$10m$ of water column gives 1 atm pressure.
$\therefore$ 20 m of water will give 2 atm pressure.