# physics, physics, physics!!!!!

posted by
**james**
.

At a depth of 10.9 km, the Challlenger deep in the Marianas Trench of the Pacific Ocean is the deepest site in any ocean. In 1960, Donald Walsh and Jacques Piccard reached the challenger deep in the bathy scaph trieste. Assuming that sea water has a uniform density of 1024km/m^(3), approximate hydrostatic pressure (in atmospheres) that the trieste had to withstand.

What is the weight of a column of water of area A of height 10.9 km.

Average height is half that, the mass is density*volume.

Pressure = weight/area

That is the external pressure on the boat due to water. Now, one has to know the internal air pressure to get net pressure, and don't forget to include atmospheric pressure at the surface: it is pressing down on the water.

hello?

can you explain this alittle more thank you :)

To get the pressure at that depth, figure the weight of a column of water above it of Area A, height h. Add the atmopheric pressure at the top. That will give you absolute pressure (weight/area) on the sub. To get the net pressure on the walls, subtract the inside pressure, which was not given.