2006-06-19 13:34:20 · 7 answers · asked by boyrambo 1 in Science & Mathematics ➔ Astronomy & Space
14.7 PSI is the atmospheric pressure at sea level. It has nothing to do with gravity.
2006-06-19 13:40:10 · answer #1 · answered by ijcoffin 6 · 0⤊ 0⤋
Air pressure at sea level is about 14.7 pounds per square inch, but it varies by up to 10% depending on weather conditions. This is why barometers are so useful. If you get a glass tube, sealed at one end, cross-sectional area one square inch and put it in a bath of heavy liquid like mercury and fill it with the liquid, then slowly lift the closed end, keeping the open end submerged in the liquid, when the top is about 30 inches above the level of the liquidthere will be an empty space above the column of liquid in the tube. It is being held up by the air pressure on the liquid in the bath. This column of liquid weighs about 14.7 pounds.
2006-06-19 14:11:49 · answer #2 · answered by zee_prime 6 · 0⤊ 0⤋
Okay, in a nutshell, if you could imagine a column of air that is exactly 1 inch by 1 inch square that is stacked vertically as far up as you can go in our atmosphere. A super huge stack of leggos per se. Then you take all of that air and SMASH IT TOGETHER into one little cube that is 1 inch by 1 inch by 1 inch, then that "sugar cube" of air would weigh 1 pound. 14.7 is just the 'average' weight. Also, you will hear this figure as being equal to 29.92 inches of mercury. Using a mercury barometer, the 14.7 pounds of stacked air is pushing on the surface of a pool of liquid metal mercury and it pushes the mercury up a tube dipped into that pool/bowl of mercury...and the distance that the mercury is pushed up would be 29.92 inches above the surface of the pool. The more air you stack (higher pressure/higher weight of air) lets say 15.0 pounds then the higher the mercury would be pushed up the straw. so 30.00 inches of mercury. Sometimes it falls. Sometimes it rises. Sometimes it is steady.
2006-06-19 14:48:36 · answer #3 · answered by Firehawk 2 · 0⤊ 0⤋
The acceleration we call gravity is 9.80 meters per second per second.
14.7 pounds per square inch is the value of atmospheric pressure at sea level.
2006-06-19 13:45:02 · answer #4 · answered by Dave_Stark 7 · 0⤊ 0⤋
i assume u mean pressure not gravity..
pressure= force divided by area... in other words there are 14.7 pounds for every square inch
2006-06-19 13:44:18 · answer #5 · answered by cuckoo meister 3 · 0⤊ 0⤋
Add up all the weight of all the air and divide it by the area of earth's surface.
2006-06-20 05:01:11 · answer #6 · answered by Anonymous · 0⤊ 0⤋
That's pressure!
2006-06-19 14:06:07 · answer #7 · answered by Science_Guy 4 · 0⤊ 0⤋