Answer
$P=-3.9\times 10^{-3}atm$
Work Step by Step
We will use the following formula for solving the question:
$P=-{\rho}gh$
The negative sign shows that the pressure in the lungs is less than atmospheric pressure.
We plug in the known values to obtain:
$P=-1000\times 9.8\times 4\times 10^{-2}=392 Pa$
$P=\frac{392}{1.05\times 10^5}=-3.9\times 10^{-3}atm$
