Calculating the time for a pressure change

AI Thread Summary
To calculate the time required for the pressure inside a closed concrete box to increase from 0.01 atm to 1 atm due to air permeability, one must understand the concept of permeability coefficient in relation to the box's dimensions. The permeability coefficient quantifies how easily air can flow through the concrete material. By applying principles from fluid dynamics and gas laws, one can derive an equation that incorporates the permeability coefficient and the box's dimensions to estimate the time for pressure change. This calculation typically requires some effort and understanding of the relevant physics concepts. Ultimately, a clear understanding of permeability and its application is essential for solving this problem.
Sam1010
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I've been searching and it seems I am not smart enough to find the solution for this...

Let say I have a fully closed box made of concrete left in air. The pressure inside the box is 0.01atm. Since it is left in air, the air will come inside the box through concrete walls(since concrete is porous) and the pressure inside the box will go up to 1atm eventually(same as outside pressure).

If I have the permeability coefficient of the concrete and the dimensions for the box, how can i calculate the time required for the inside of the box pressure to go up to 1 atm from (0.01 atm)?
 
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Hello Sam, ##\qquad## :welcome: ##\qquad##!

This looks a lot like an exercise or homework, and at PF that means an effort from your side is required:
What is the meaning of a permeability coefficient in this context ?
 

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