You are assigned the design of a cylindrical, pressurized water tank for a future colony on Mars, where the acceleration due to gravity is 3.71 meters per second per second. The pressure at the surface of the water will be 125kPa , and the depth of the water will be 14.2m . The pressure of the air in the building outside the tank will be 91.0kPa .

I know how to solve it cause i googled the darn thing, but I don't know why the solution is the way it is.

There is an upward force exerted by the pressure of the air. This doesn't make sense to me because there is no water below the container, right?

the pressure can't go through the ground right?


Successful explanation gets 40fg. I promise I will give the fg if I am satisfied with the explanation given.

This post was edited by thestoryofisaac on Aug 30 2014 02:28pm

This is a total shot in the dark but my guess would be the air pressure on the tank causes the tank to compress which leads the water to exert an upward force as it tries to expand.

Honestly not the best question, especially without a picture

It's a lot easier if you think of it as a cylinder with a movable bottom
pressure at bottom of tank = weight of water + known pressure above water
net pressure at bottom is pressure at bottom (which is outward,down) - air pressure in room