Imagine you have a closed in space and a set number of air molecules. The molecule bumping into each other and the sides of the container is what causes the air pressure. If you decrease the volume in half, then you double the number of collisions. This causes the air pressure to double also. The air molecules don't go anywhere, they just get closer together as the pressure goes up and further apart when the pressure goes down. If you dropped the temperature to absolute zero, so the air molecules didn't move, then your air pressure would be zero.
2007-01-27 11:18:45
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answer #1
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answered by Mr Cellophane 6
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Air density is directly related to air pressure. Think Mexico City and why foreigners don't drink the water or having trouble breathing while climbing the mountains. First, because Mexico City is 4,000 ft. above sea level, water can't boil at 100 degrees celsius (it boils at 96 degrees) due to an increase of air pressure (aka atmospheric pressure). Since water boils at 96 degrees it can't kill all the bacteria which is bad for us. The same concept applies to climbing, the higher you go up, the less dense the air quality is, which is why you must breathe faster. Air doesn't go anywhere, its just that the higher you go the more pressure you find which affects the density of air.
I hope this helps.
2007-01-27 19:36:23
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answer #2
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answered by Trish 2
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The pressure of any fluid is given by the formula:
pressure = density x g x height
where g is the gravitational constant.
This is also valid for air. A denser air causes higher pressure. Also this relation explains why pressure is lower in high altitudes. The height of air above this altitude is smaller when compared to sea level.
The concept of pressure is explained as the collision of fluid particles with a body. The air molecules hitting a surface causes the air pressure. A denser air mixture means higher rate of collision, i.e higher pressure.
2007-01-27 19:28:44
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answer #3
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answered by canozerus 1
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Density is related to air pressure by the following equation
PV=nRT P is pressure. V is volume, n is the molar mass of the gas, R is the Ideal Gas Constant equal to T is Temperature and is in absolute degrees Kelvin.
for air we can assume that PV = MrT where the new r is the specific gas constant for air equal to 287J/(KG*K)
Density is just then simple M/Vso that Pressure is related to air density by P = (density)*r*T
2007-01-27 19:20:24
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answer #4
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answered by djleprechaunx 1
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