What Is the Net Force on a Submarine Hatch at 8.5m Depth?

[queen2008]

Homework Statement

a miniature sub is lowered to a depth of 8.5 m in sea water of density 1030 kg/m^3. The interior of the sub is maintained at a pressure fo 1.00 atm. Find the net force that must be withstood by a 1.5 diameter hatch which leads to the insisde.

Homework Equations

F= PA P= p + density X gravity X height

The Attempt at a Solution

Change in Pressure = 0 so P= 1030 X 9.8 X8.5

 

[mgb_phys]

Hint, there is also one atmosphere of pressure pushing down on top of the water, and one atmosphere of pressure pushing out from the inside of the sub.