Garden Antiques For Sale

Why do the shades over an open window pull back to the window when I yank open the front door?

Does it have something to do with how the moving air works?

air rushes through the front door, where the pressure outside, since outside air is always moving and changing local pressure, sucks air in the room back out of the window and the moving air slams the shades. If you think about it, while the door there is no air flow through the room, so the force of air coming through the window will be almost zero as pressure outside equals pressure inside. But when the door is opened air is free to enter or leave the window and door, so the room is no longer closed as a system; air flows through it and pulls the shades shut.

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