Answer:
[tex]F_{int}[/tex]= 9.21 104 N
Explanation:
The definition of pressure is
P = F / A
In addition, the pressure varies with the depth by the equation
P = ρ g h
Let's write the second law and Newton for the hatch
[tex]F_{int}[/tex] - [tex]F_{ext}[/tex] = 0
[tex]F_{int}[/tex] = [tex]F_{ext}[/tex]
[tex]F_{ext}[/tex] = P A
Water pressure pressure plus atmospheric pressure
P = [tex]P_{atm}[/tex] + ρ g h
The hatch is a circle of radius = 0.18 m
A = π r²
[tex]F_{ext}[/tex] = ([tex]P_{atm}[/tex] + ρ g h) π r²
Let's calculate
[tex]F_{int}[/tex] = (1,013 105 + 1025 9.8 80) π 0.18²
[tex]F_{int}[/tex] = 9.049 105 0.1018
[tex]F_{int}[/tex] = 0.921 105 N
[tex]F_{int}[/tex]= 9.21 104 N