what cuases air pressure?

Answer 1

too many beans?
Bascially air pressure results from the force of air molecules against a surface. Air molecules are small but there are a lot of them and they have a small mass each. When they continually bombard a surface, the force/area is the pressure.

Answer 2

Uneven changes in temperature. Several factors affect the way the air above the surface of the earth is heated. Cloud cover, the reflectivity of the surface, surface topography, and whether the surface is land or water. When air is heated, it becomes less dense (lower pressure) and rises. Cooler, higher pressure then moves in. This creates the wind.

Answer 3

Animal and Roadkill basically have it right. Think of air as being made up of lots of little superballs (really atoms and molecules) that are constantly bouncing around. When air molecules bounce off something, they push against it. The net result of all these little pushes on the surface of things, is called air pressure.

(If whoever gave animal and roadkill thumbs down ratings still doesn't believe this, I propose you suggest yourself to the following demonstration. Have all of your friends line up in front of you and have them throw superballs at you.)

Answer 4

I like the animal answer but will expand on it. The air molecules bombard surfaces because they are bouncing around (kinetic energy) and bounce off each other and everything else.

They have a mass and velocity so the pressure is actually an indication of their momentum, and their number.

Answer 5

Air pressure is caused by the weight of the air in the atmosphere. It is the total amount of weight of the air (and yes it does have weight) and can be divided over the area it is on.