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Homework Help: Force on an object submerged

  1. Nov 21, 2008 #1
    1. The problem statement, all variables and given/known data

    In this problem, please make sure to use the density of seawater = 1025 kg/m3.

    The bottom of the Mariana Trench, located in the Pacific Ocean, is about 11,000 m below the ocean's surface, making it the deepest ocean depth on Earth.
    If an underwater vehicle were exploring the region, at a depth of 10550 m,

    a.) What force would the water exert on the vehicle's circular observation window, which has a radius of 0.1 m?

    2. Relevant equations
    P= pgh

    3. The attempt at a solution
    P=pgh=1025 x 9.81 x 10550= 1.06 e8 Pa

    i don't really get how the radius relates...
    and if i'm suppose to find the buoyant force, how do i find it without the mass or volume?
  2. jcsd
  3. Nov 21, 2008 #2

    Doc Al

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    Staff: Mentor

    How does pressure relate to force?
  4. Nov 21, 2008 #3


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    Science Advisor
    Homework Helper
    Gold Member

    You calculated the pressure correctly; the problem wants not the buoyant force, but rather, the force of the water pressure on the window. How is force and pressure related?
  5. Nov 21, 2008 #4
    F=P x A....but i don't have the area...
    i know radius is 0.1 m, but i don't know the other dimensions.
  6. Nov 21, 2008 #5
    ohhh its a circular window! ahah i misread it.
    so the area of a circle :
    A=pi r^2=pi(.1m)^2=.031416 m^2

    so F= 1.06 e 8 x .031416 =3.33 e 6

    mmmk thanks :)
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