Hot answers tagged water
7
The pressure itself doesn't really matter as Mark pointed out. Neither does the bends if you stay at the same pressure - it is caused by gas coming out of solution and forming bubbles as you rise (and the pressure drops)
The real challenge at very deep deaths is the chemical effects of gases at high pressure.
Normal air scuba is limited at around 40m ...
5
Double the ammount of water does not need doulbe the ammount of time to heat, since while the energy needed is doubled indeed, losses due to vaporization and radiation from the kettle should be approximately constant.
You can plot the time needed for a given ammount of water to boil and try to fit a function into that. With two data points you can manage to ...
5
One has to study the geologic structure of the earth:
Figure 1: The interior structure of the Earth, with a close up of the lithosphere/asthenosphere boundary. Redrawn from Plummer & McGeary, 1997.
There exists the Oceanic crust, which is the boundary between the bulk of water and the lithosphere. It has very low permeability and thus the oceans ...
3
A diver's body is basically made of water, and water is incompressible to a good approximation over the relevant pressure range. So the physiological effect of the water pressure itself will be negligible: I expect there is no problem with diving at 700m in soft suits in that sense.
However, in order for the diver to inflate her lungs, she must have air ...
2
Gravity. As nearly as possible, the materials of the earth have migrated vertically so as to approach an arrangement closer to hydrostatic equilibrium. Liquid water or water vapor is much less dense than rock, and can flow through connected porosity in the earth's crust. In rock at depth, the weight of the overlying rock deforms the rock, collapses pores, ...
2
I think the answer to this is actually pretty complicated, and has to do with chemical changes that take place in rocks during subduction. Rocks generally do like to absorb water (they become hydrated), but under the intense pressure and temperature of the subduction zone, the water molecules and the minerals become separated. I don't know exactly why this ...
2
No, it cannot. With coil heaters, the electricity flow is insulated from the water. If there was any way for electricity to flow from the coil to the water, the coil would be shorted, electricity would no longer flow through the coil, and you wouldn't have any heating.
Electrically heating water has the same effects as heating it over a stove. There may be ...
1
The other answers already treat decompression sickness, but in addition to the submarine scenario:
How long would one have to hold one's breath? A good diver can apparently maintain something around 0.5 m/s (plus some Buoyancy due to the air in their lungs), so even for a Civil submarine at around 30 m depth, they'd have to hold their breath for a minute. ...
1
The compressive effect on the body itself is not a problem because we are composed of incompressible fluids and solids. All gas filled cavities in a healthy person are connected by tubes to the outside so that the internal pressure can be equalized as external pressure increases.
A deep diver is affected by a variety of other problems that can be corrected ...
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Yes, colouring the water could make the pool heat faster, though whether the colour you noticed has an significant effect is debatable.
Swimming pools exchange heat with their environment by conduction through their walls, evaporation at the surface and absorption of sunlight. I have little direct experience of swimming pool thermodynamics, but some ...
1
1) The absorption on a tooth brush or a wash cloth is caused by capillary action and wicking. The hairs of the tooth brush will be hydrophilic (they 'like' water) and this will result in the small spaces between the hairs pulling water in to lower the total surface energy. You can write a force balance for the height a liquid in a tube of radius $r$ will ...
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