## Fundamentals of Physics Extended (10th Edition)

$Force =7.2 × 10^{5}$ $N$
Hydrostatic pressure at height $h$ below the surface is given by: $pressure=\rho_{o}+\rho g h$ This is the pressure on the submarine from outside. The net pressure ($P_{net}$) is the pressure difference between the pressure outside and internal pressure. So, $P_{net}=[\rho_{o}+\rho g h ]-[ internal$ $pressure]$ Substituting the known values and solving gives: $P_{net}=[1 atm+1024$ $kg/m^{3}\times9.8$ $m/s^{2}\times 100 m]-[1 atm]$ $P_{net}=1.003\times10^{6}Pa$ We have : $Force=P_{net}\times Area$ Substituting the known values in the above equation and solving gives: $Force =[1.003\times10^{6}Pa] \times [1.2m\times0.60m]$ $Force = 7.2\times10^{5}$ $N$