2006-09-10 16:49:32 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Earth Sciences & Geology
Because a pump doesn't "raise the water."
It merely creates a lower pressure area and the atmospheric pressure pushes the water up to fill the low pressure area. The atmospheric pressure is approximately 29" Hg - and that is equal to approx. a column of water 30 feet high.
This is why deep water wells have the pump in the well - because the water can be pumped up (pushed) to any height the pump is capable of.
2006-09-10 17:00:01 · answer #1 · answered by LeAnne 7 · 2⤊ 0⤋
When you suck up water with a straw, or a vacuum pump, you're creating a partial vacuum above the column of water. It's the air pressure on the water surrounding the raised water column that pushes it up. So the highest column of water that can be sucked up weighs the same as atmospheric pressure; 1kg/sq.cm., and a column of water 1 sq.cm. in cross section which weighs 1 kg is 34 feet (10 metres) high.
2006-09-10 17:20:28 · answer #2 · answered by zee_prime 6 · 0⤊ 0⤋
Because ordinary pumps require air pressure to raise the water, and raising it to more than 34 feet would require more air pressure than exists at ground level.
2006-09-10 16:59:06 · answer #3 · answered by cdf-rom 7 · 0⤊ 0⤋
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2017-02-27 23:30:14 · answer #4 · answered by Corinne 3 · 0⤊ 0⤋