Question

what is the pressure on the swimmer 20 metres below the surface of the water pond take the atmosphere pressure has 1 into 10 power 5

Answer 1

3 atm is the correct answer

usually 2 atm answer calculated by by students but we also add 1 atm as atmospheric pressure Po

Answer 2

Answer: The swimmer pressure is $\bold{197 \times 10^{5} P a}$  

Solution:

The given situation suggest the swimmer in the pond is at a certain depth experiencing pressure from the water as well as the atmosphere therefore the pressure is calculated as follows -

As we know that, Pressure = atmospheric pressure + pressure inside water

Total pressure P = atmospheric pressure $\bold{P_{0}}$ + Pressure inside water $\bold{P_{w}}$  

$\begin{aligned} P &=P_{0}+P_{w} \\ P &=1 \times 10^{5}+h \rho g \\ P &=1 \times 10^{5}+20 \times 1 \times 9.8 \\ P &=1 \times 10^{5}+196 \\ \bold{P &=197 \times 10^{5} P a . \end{aligned}}$