Air pressure difference in inside and outside of house

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Discussion Overview

The discussion revolves around the concept of air pressure inside and outside a house, exploring why the pressure remains consistent despite the apparent difference in air volume. Participants engage with the fundamental principles of pressure and its implications in a household context.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant defines pressure as force per unit area and notes that atmospheric pressure is approximately 101,325 Pa, questioning why this pressure is the same inside a house despite less air volume.
  • Another participant explains that the walls of a house cannot withstand the atmospheric pressure, likening them to the soft walls of a balloon, and argues that the air pressure inside is equal to the outside pressure due to the force exerted by the air.
  • A participant introduces a thought experiment involving a bathroom scale placed at the bottom of a pool, suggesting that the scale would read the same pressure regardless of the water above it.
  • There is a follow-up on the bathroom scale scenario, indicating that the reading would change if a person were standing on it, but clarifying that the initial question was about the scale itself.

Areas of Agreement / Disagreement

Participants generally agree on the principle that air pressure is consistent inside and outside a house, but there are differing interpretations and clarifications regarding the implications of pressure in different scenarios, particularly with the bathroom scale example.

Contextual Notes

The discussion includes assumptions about the nature of pressure and the effects of surrounding environments, such as water in the pool scenario, which may not be fully explored or resolved.

Who May Find This Useful

Individuals interested in physics, particularly those curious about fluid dynamics and pressure concepts, may find this discussion relevant.

fsb257
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Pressure is defined like FORCE/SURFACE [Pa] so the outside pressure close to the Earth is atmosphere pressure (101 325 Pa) defined by the mass of air/surface.Why is the same pressure in my house? There isn't much air like in outside...Thanks for the potential answer an sorry for the bad english.
 
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Good question, should be asked by anyone who thinks about air pressure.

Air pressure of 100kPa is about 10 tons/m^2
The walls of your house can't withstand this sort of pressure, the are like the soft walls of a balloon.
So the huge force of the air pressing down on the roof also presses down on the air inside to give the same force.

Picture the air like a pile of bricks on a weighing scale, now put a thin piece of paper between two of the brick to represent the roof of the house, it doesn't change the weight on the scale.
 
If i put a bathroom scale on the bottom of a pool , would the scale read greater less or the same , it would read the same .
 
cragar said:
If i put a bathroom scale on the bottom of a pool , would the scale read greater less or the same , it would read the same .

Not if you're standing on it.
Above the pool, your weight read, say, 150.
Bottom of pool your weight reads, say, 75 or possibly much less.

But I think you were just talking about the scale itself.
 

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