# Homework Help: Force on an object submerged

1. Nov 21, 2008

### iseidthat

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. Nov 21, 2008

### Staff: Mentor

How does pressure relate to force?

3. Nov 21, 2008

### PhanthomJay

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?

4. Nov 21, 2008

### iseidthat

well
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.

5. Nov 21, 2008

### iseidthat

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 :)