Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.

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2answers
116 views

How does a rising bubble take a dome-like shape?

Since I have swam on the swim team for most of my life, I am very familiar with bubbles. I know a raindrop falling through the sky gets its shape because it is the most aerodynamic shape, but how come ...
1
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0answers
11 views

Capillary bridge force function given volume and distance

Given two surfaces and a fluidic glue with sufficient adhesion, what is the force provided by the capillary bridge provided the cohesive properties of the glue, volume, and distance between the ...
1
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1answer
85 views

Why does the bulk modulus of water have a maximum at around 60-70ºC

So I'm doing some water hammer analysis and was calculating bulk modulus of water as a function of temperature. I took the speed of sound and density of water as functions of temperature and ...
0
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2answers
285 views

When Sugar Is Added to Water, How Does the Mass Change, and How does That Affect the Water's Density and Boiling Point?

I can't find a good answer anywhere. How does the amount of sugar added change the boiling point, mass, and density of water? Does it affect the mass or the volume? Or both?
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1answer
355 views

If I mix 1 unit of water at at 30C° with 1 unit of water at 60C°, is the resulting water at 45C°? [closed]

I'm curious how temperatures work when mixing water. I'm not very good at physics but I'm always learning. Let's say I've 1 gallon of water at 30C° and 1 gallon of water at 60C°, and I mix them ...
1
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0answers
84 views

What pressure will stored water at height provide from a pipe? [closed]

A big open tank is filled with water ($10000$ litres) and kept at a height $15$ metres from ground. At its bottom, a pipe of $1.5$ inch diameter and $10$ meter length is connected. The water is ...
0
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0answers
49 views

Entropy changes of water

I have a few questions regarding entropy and water. Suppose you cool down water so that it freezes at $273.15K$. How is entropy positive in this case? I have a feeling it may have to do with the ...
0
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1answer
28 views

Can there be net condensation into a pool of water?

I'm curious about the equilibrium of evaporation and condensation. Given that the surface area of a dehumidifier's evaporation coil at 4C is proportional to the rate of condensation, how would the ...
0
votes
1answer
64 views

Time to decrease water temperature by 5F from different initial temperatures

Is the time to (naturally) decrease temperature of water by 5 degrees the same, regardless of the initial temperature? Imagine 3 glasses of water (a, b c) in a room temperature of 70F. There are 3 ...
0
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1answer
95 views

How does pressure increase underwater?

How it is that when we go deeper in water(seas or oceans) the pressure increases, while water(generally liquids) are incompressible?
0
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3answers
111 views

Is there an way water can burn or cause fire?

Water known as the fire extinguisher.What is the possibility watere being the fuel to fire. "Pure water"
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1answer
30 views

Water's Specific Heat Capacity as an Outlier

Can the specific heat capacity of water being ridiculously high as compared to other substances be explained at a molecular scale?
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0answers
90 views

Finding an equation for the cooling curve of water with respect to surrounding temperature

I would like to find a general equation that describes the cooling curve of water from 100 degrees Celsius to the surrounding temperature $T_s$ against time (say, in seconds). As far as I know and ...
0
votes
1answer
48 views

Viscosity of Muddy Water

How do I calculate the viscosity of muddy water at 25 deg C and knowing the weight of undissolved solids either SiO2 or Al2SiO5 in H2O, grain size < 150 microns? Do I have enough information to get ...
0
votes
0answers
33 views

What are the physics principles behind “amphibious” camera lens windows?

Underwater camera housings have a window through which the lens looks. When the camera surfaces, a couple of things can happen, and I've seen both captured in the camera footage. In one case, water ...
2
votes
1answer
90 views

Why is modelling water so difficult?

There are several models of water that have come into existence so far. Nevertheless, there is no one particular model which effectively gives all the properties of water correctly. A model like TIP3P ...
4
votes
2answers
77 views

Why does soaking something soften it up [duplicate]

Apologies if this is duplicate, I've dug around and can't find it. If you leave a sponge/cloth out to dry for a while it eventually becomes slightly stiff. Upon wetting again, however, it softens up ...
0
votes
1answer
357 views

Why do hot tubs dehydrate you? [closed]

I was just sitting in a hot tub for a few hours with friends, and we all noticed we really wanted to drink some water. We felt dehydrated. I tried looking up why hot tubs dehydrate you and all I got ...
0
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2answers
260 views

Does water follow the path of least resistance

I am having hard time proving this either right or wrong. Let's take for example a river, does the water flowing down follow the least resistant path?
4
votes
2answers
130 views

Water bombing - risks and possibilities

I just saw a video on youtube, where an excavator drops a load of water on a car, destroying it completely. I also saw a video with a fire-fighting plane dropping even more water on a burning truck. I ...
-2
votes
2answers
105 views

Is pure water electrically conductive? [closed]

I know that water with some ions dissolved is a good conductor. I wonder whether it is true for pure water?
0
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1answer
83 views

Paper Napkin Folded

Why folded napkins are better absorbing water than ordinary napkin. I think there must be related to cohesion of water element. Water are captivated between layers because they appeals each other or ...
0
votes
0answers
28 views

What do water stains make things appear dark? [duplicate]

If a piece of grey tarmac is damp after the rain, it appears darker. If I spill water on my carpet, the damp patch is darker than the rest of the carpet. Generally speaking, a lot of things appear ...
3
votes
3answers
2k views

Why does water reflect light?

Why does water reflect light? What is actually happening when light is reflected by water? We know why metals reflect light; water, however, is not metal, but it still reflects light and we can see ...
0
votes
1answer
46 views

How long can water hold elevated pressure and energy after opening pressure cooker lid?

I noticed today that the water warmed up in pressure cooker (1.5 ATM) dissolves sugar much faster and much more than water cooked in 1 ATM. I am interested in how long can water hold the high ...
2
votes
2answers
83 views

Is it possible to mix a drink with a non-standard phase of ice?

Would it be possible to safely cool and drink a glass of water with anything else than the Ih form of ice? Here and here you can see that some alternative forms of ice have a higher density than ...
1
vote
1answer
94 views

Why does water boil differently in a microwave than over a flame?

Over a flame, small bubbles will start to form on the bottom of the pot, and as the average temperature rises, the bubbles will become larger until they start rise to the top. As it gets even hotter, ...
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2answers
116 views

movement of water in plants

Books say that water moves from places with a high water potential to places with a low water potential. The movement of water in plants are explained because water potential is lowest in leaves and ...
2
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0answers
85 views

Suction from flowing water

My memory from physics says yes but I want to check. Our pool is dirty and our vacuum is broken. If I were to stick the vacuum hose into the pool drain, would the flow of water going into the drain ...
0
votes
1answer
114 views

How does a water-steam mixture behave?

Namely, if I mix a flow of steam that has density $\rho_s$, velocity $v_s$, and pressure $P_s$ with a flow of water that has pressure $P_w$, velocity $v_w$, and density $\rho_w$, how can I find the ...
2
votes
1answer
84 views

Why does water remain as a “hemispherical bubble” when it falls on a page?

Today while drinking water, a drop of it accidentally felt on a page of my book, and I was thinking that, "Oh my god! The water will spread instantly, making the part of page wet". But, I observed, ...
63
votes
7answers
12k views

When I boil a kettle, what stops all the water from turning (exploding!) in to steam in one go once it reaches 100°C?

While making a cup of tea in the office kitchen, a colleague asked me this question and neither of us could answer with any certainty. We're guessing it has something to do with the pressure of the ...
4
votes
3answers
1k views

Why is boiling not just a surface phenomenon?

The boiling point of a liquid is defined as The temperature at which the vapor pressure of the liquid is equal to the external atmospheric pressure. That being the case, why, in a pot of boiling ...
12
votes
3answers
262 views

Crown shape in water waves?

Watching this slow motion video of waves caused by a droplet falling on water, I am puzzled by the first wave shape. The first wave rises with circular symmetry as I expected, but is not even in ...
3
votes
1answer
169 views

Calculation of long-range forces in Molecular Dynamics - Ewald summation

I am trying to write a code to calculate the potential and forces, for the same using ewald summation.For this purpose, the formula for potential and force I have used is : $$ U = U^{(r)} + U^{(k)} ...
0
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3answers
28 views

Breathe Air from a source without any pressure compensation?

I just thought about what I'd do if I was on a sinking ship and of course breathing was the first thing that came into my consideration. Now imagine the ship's front going up and the room you are in ...
0
votes
1answer
231 views

What wavelength of light is the least absorbed by water?

As I understand it, an infrared laser range finder will not work underwater because the infrared rays are heavily absorbed by water. What wavelength (optical, ultraviolet, microwave, etc.) of light ...
2
votes
1answer
88 views

Why is it that not the entire surface of Earth is covered by water? [closed]

Isn't it a coincidence that our planet is mostly but not completely covered by water? Is there a reason why less water or more water is not compatible with intelligent life? Also, isn't it a ...
0
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3answers
319 views

Does ice made out of salt water melt slower than ice made of pure water?

I'm trying to make this whole bunch of ice bottles to cool down my little aquarium. What I want in the ice bottles is that, fter freezing the whole bottle full water into ice, I need the ice to melt ...
9
votes
2answers
435 views

Water evaporation problem. Exercise from Feynman's lectures

I read lectures of Richard Feynman and try to solve problems and I have some trouble with a problem on water evaporation. A glass full of water is left standing on an average outdoor window in ...
3
votes
1answer
287 views

Why does water get significantly colder while falling through the air?

I think we've all experienced this effect. You turn on the shower and the stream of water at the shower head is a fair bit hotter than the water towards the bottom of the stream. Alternatively, if you ...
0
votes
1answer
124 views

Can capilliary action move liquid against gravity?

I was wondering if it was at all possible to very slowly suck up water from a cup with a rope, and then deposit the water into another cup on a 3cm thick book or similar object. Here is an example ...
0
votes
3answers
70 views

Kayaking against the wind is faster than with wind in my back? [closed]

Today I was kayaking on a lake. I noticed that there is not very strong, but noticeable wind. There were also currents, all going in one direction, probably caused by wind. One more thing I realized ...
2
votes
2answers
804 views

Why does a paper towel absorb water upwards?

When I touch a paper towel to a drop of water I can see the water move upwards into the paper towel. What force is responsible for this gravity defying phenomenon?
0
votes
1answer
63 views

Efficiency of a gravity feed hose

If I am trying to fill a large cylindrical container with a gravity feed hose, would it be more efficient, time-wise, to drill a hole in the bottom of the container for a greater initial pressure ...
0
votes
1answer
856 views

Why does surface tension of water-ethanol binary mixture decrease with increasing concentration of ethanol?

I was thinking that it must be due to weaker hydrogen bonding in ethanol than in water. But then I learnt that Raman Spectroscopy and viscosity measurements suggest that upto a certain ethanol ...
0
votes
1answer
41 views

Why toilet paper is softer in moist air? [duplicate]

After a hot shower,the air from the bathroom is full of water steam,right? How does the air affect the texture of the toilet paper?I mean,the toilet paper it seems to be softer,but why? Can someone ...
0
votes
0answers
42 views

How long does it take for disturbed water to stop making sound?

Suppose I have a bowl with water or another liquid. The water from the bowl is perfectly quiet. Then I throw a stone in the water and I wait. How can I calculate the time after which the water is ...
1
vote
2answers
132 views

Greater pressure perceived when wearing waders

A few days ago I went for a hike in the waters of a river. I was wearing waders like the ones you see in the following picture: I don't understand why the pressure I perceived on my legs when the ...
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0answers
28 views

Can I disperse a droplet with electromagnetic fields?

If I have a droplet of water, can I apply an electromagnetic field in order to disperse the droplet into smaller subdroplets (tiny vapor) and fill a space with them? The same way that magnetic dust ...