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A porthole on a vertical side of a submarine submerged in sea water has a diameter of 2r feet. Sea water has a weight density of 64 pounds per cubic foot. Find the fluid force on the porthole, assuming that the center of the porthole is d feet below the surface.

Relevant Equations:

fluid pressure= weight * height aka p=wh

fluid force= p*A, A being the area the force is exerted on.

Attempt at Solution:

I know its going to be the integral of p*A bound from zero to some number. I thought that p might equal 64y (the weight times the height), but that seems too simple and I think "d" has to be incorporated into that part of the integral somehow. For A, I used the equation of the circle, x^2 + y^2 = r^2, A=y= square root (r^2-x^2). That's where I stopped, because none of that seems right, I feel like I need to have everything in terms of one or two variables in order to integrate and actually find the fluid force. P

Please help, I am so stuck and frustrated, I drew a diagram but it's not helping much! I desperately need to figure out the correct answer to this problem!!!

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# Homework Help: Fluid Force Problem- Caclulus II

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