Pressure of 11,000m Water Column: Crushing or Equal to Bottom of Ocean?

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Discussion Overview

The discussion revolves around a thought experiment involving a cylinder filled with water to a height of 11,000 meters, comparing the pressure experienced inside the cylinder to that at the bottom of the ocean. Participants explore the implications of water pressure, the effects of cylinder dimensions, and the calculations involved in determining pressure differences.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether a person would be crushed by the water pressure in the cylinder, suggesting it would be equivalent to being at the bottom of the ocean.
  • Another participant agrees that if the cylinder does not burst and disregarding entry and exit methods, the pressure would be the same in both scenarios.
  • Several participants inquire about formulas to calculate pressure differences and the specific pressure at 11,000 meters depth.
  • One participant mentions that a wider cylinder would be necessary for a larger individual, prompting a discussion on whether this would affect the pressure experienced.
  • There is a calculation presented indicating that 11,000 feet of water creates approximately 4769 psi of pressure, though this is later corrected to reflect the correct height in meters.
  • Another participant points out that the density of seawater and atmospheric pressure at sea level should be considered in the calculations, indicating that the pressure at the ocean bottom is worse than at the surface of the cylinder.
  • Clarifications are made regarding the conversion of pressure units and the significance of atmospheric pressure in the context of the thought experiment.

Areas of Agreement / Disagreement

Participants express differing views on the calculations and implications of pressure in the cylinder versus the ocean. There is no consensus on the exact pressure values or the relevance of atmospheric pressure in the discussion.

Contextual Notes

Some calculations presented are based on assumptions about water density and atmospheric pressure, which may not be universally accepted or agreed upon. The discussion includes corrections and refinements of earlier claims without reaching a definitive conclusion.

Gondur
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Suppose a cylinder was made. It is the same height as the deepest part of the ocean to the ocean surface - about 11,000 metres and about 1 metre wide.

The cylinder was filled with water right to the top and stood on the Earth's surface.

A small hole at the bottom of the cyclinder was opened and you jumped inside.

Would you get crushed by the water pressure of the weight of the column of water?

Would it be the same as being at the bottom of the ocean?
 
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Gondur said:
Would you get crushed by the water pressure of the weight of the column of water?

Would it be the same as being at the bottom of the ocean?

If we disregard the cylinder bursting, and disregard how you get in and out, yes to both.
 
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Nice thought experiment. Do you have any formulas we can use ? What is the pressure difference between the ocean surface and the 11000 m deep bottom ?
 
My uncle is very fat. He needs a 3m wide cylinder. Would that make a difference ?
 
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BvU said:
Nice thought experiment. Do you have any formulas we can use ? What is the pressure difference between the ocean surface and the 11000 m deep bottom ?

It doesn't matter if the water is in the ocean or the cylinder. 11,000 feet of head creates 4769 psi of pressure.
 
Now that we have fun, @Gondur: can you reproduce this pressure ? I get a different result. Lots (well...) of big and small differences.
 
Water column is 11000 m, not 11000 feet -- factor 3 worse
Density of sea water is around 1020 kg/m3 -- offsets the 9.81
Pressure at sea level is higher than at 11000 m height -- so the sea bottom is worse

Don't want readers to get the wrong idea.. :rolleyes:

All in good spirit.
 
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BvU said:
Water column is 11000 m, not 11000 feet -- factor 3 worse

Whoops, thanks for correcting me 11000m of head is 1078 bars of pressure, or 15642 psi.

BvU said:
Pressure at sea level is higher than at 11000 m height -- so the sea bottom is worse

Do you mean the 1 bar atmospheric pressure at sea level? Not very significant, and I think it just confuses the OP who was just wondering about the equivalence of open bodies of water compared to cylinders.
 

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