Greentext

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This is a place to share greentexts and witness the confounding life of Anon. If you're new to the Greentext community, think of it as a sort of zoo with Anon as the main attraction.

Be warned:

Anon is often crazy.
Anon is often depressed.
Anon frequently shares thoughts that are immature, offensive, or incomprehensible.

If you find yourself getting angry (or god forbid, agreeing) with something Anon has said, you might be doing it wrong.

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Early_To_Risa@sh.itjust.works

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Anon's in trouble (sh.itjust.works)

submitted 4 months ago by Early_To_Risa@sh.itjust.works to c/greentext@sh.itjust.works

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[–] anindefinitearticle@sh.itjust.works 7 points 3 months ago* (last edited 3 months ago) (2 children)

Let's convert to metric so we can tell.

15 ft is about 5 m.

Water pressure increases by 10,000 pa per meter (rhogh, rho=1000 kg/m^3, g~10m/s^2), so total pressure is 50 kpa, or 1/2 earth atmospheric pressure.

One side of that hole has ambient pressure of 1 atm. The other side has that plus water pressure totalling 1.5 atm.

A pressure is just an energy density. Multiply by the cross-sectional area of the interface to get the energy gradient across the interface. An energy gradient is a force. We don't have a measure of the cross-sectional area of the hole, but if we expect a person to fit through let's call it 1m^2.

50 kpa = 50 kJ/m^3, so total force felt across this opening is 50kN which is the equivalent weight of five metric tons.

Size of the hole absolutely matters. If it's only the size of a fist (10cm x 10cm) then instead of 5 metric tons it's only 50 kg of equivalent weight, or about the weight of a person and easily survivable.

[–] UltraGiGaGigantic@lemmy.ml 3 points 3 months ago

[–] victorz@lemmy.world 2 points 3 months ago (2 children)

Let's convert to metric so we can tell.

15 ft is about 5 m.

Water pressure increases by 10,000 pa per meter (rhogh, rho=1000 kg/m^3, g~10m/s^2), so total pressure is 50 kpa, or 1/2 earth atmospheric pressure.

This is very interesting. I like unit conversions.

What I did was just take 21-14 psi, and then converted that to bar or atm. I got a number close to ½.

I was like, half an atm? Can't be that bad? I can handle 1 full mf atm literally all mf day mf.

But I guess that's different somehow? I just don't understand how yet. If anyone would care to go into it with me... 🙏

[–] weker01@sh.itjust.works 2 points 3 months ago

Remember a vacuum does not have suction it's the air that presses things under vacuum together. One atm is actually quite a lot but we can withstand that as it's pressing at us from all sides including inside.

See this example of how strong 1 atm can be