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Air pressure difference in inside and outside of house

  1. Jan 12, 2010 #1
    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.
     
  2. jcsd
  3. Jan 12, 2010 #2

    mgb_phys

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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.
     
  4. Apr 4, 2010 #3
    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 .
     
  5. Apr 5, 2010 #4
    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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