0
$\begingroup$

If you have a container that has a hole in the bottom to allow water into it, and place it in the water so that it is partially filled with air, what would the pressure difference be between the inside and outside of the container?

My thoughts are that the water would compress the air to the same pressure (at 300 ft this would be about 150psi) making there be no net difference between the inside and outside of the tank.

The purpose of this question is to determine if a vessel for a submersible would have to be pressure rated to the water pressure at the max depth, no pressure, or something in between.

enter image description here

$\endgroup$
1
$\begingroup$

Yes it is the same pressure inside the container as per Pascal's law. The entrapped air will play a role in buoyancy and is used by submarines and some fish.

$\endgroup$
1
$\begingroup$

In the water the pressure is the same along each horizontal section and decreasing as one goes down.
The pressure of the air in the container will be the same as the pressure of the water at its surface inside the container.

The air pressure at the top of the container would be higher than the pressure of the water outside the container at the same horizontal level.

If the container goes lower then the water pressure on the air would increase and so the volume of the air would decrease and the pressure difference across the top of the container would decrease.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.