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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8
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2answers
657 views

Why things get dry (meaning from water)? [duplicate]

When I leave wet clothes in the open air, they will get dry over time by themselves even at room temperature. I know that somehow the water becomes vaporized; it's not "disappearing". For that, it ...
3
votes
1answer
393 views

Lifting a wet object off a table

When there is a film of water in between an object and the tabletop it rests on, it is difficult to pull the object directly upward. However, when you slide the object, it comes off easily. What is ...
1
vote
1answer
38 views

Water + RF + Spark = Continuous Fire

Can anyone explain the physics of what is happening in the following video? https://youtu.be/p8xYUDiSGDk?t=37 Is this process Radiolysis? At what radio frequency & power level is h20 ...
1
vote
1answer
113 views

Using water pressure as pushing force in a floating bath tub? [closed]

Does physics allow for water pressure to work in this way? if so What formula can prove this? (backup link 1, backup link 2)
1
vote
0answers
42 views

What is the maximum theoretical height upto which our oceans can rise? [closed]

The question is framed from a physics point of view so we will assume water is an indefinite resource. All I am interested in is if we go on adding water into our oceans then what is the maximum ...
2
votes
2answers
182 views

What actually makes boiling happen?

Boiling can be breezed over easily with a few rudimentary diagrams and a couple equations, but I seek a deeper explanation. The definition of boiling is that the vapor pressure in the liquid is ...
1
vote
2answers
94 views

How does calblock (water softener) work?

This "calblock" device claims to prevent limescale accumulation on water heaters in a washing machine. It sits between the water faucet and the washing machine; the water passes through it. I cannot ...
1
vote
2answers
151 views

Heat Losses from water pan due to vaporisation before boiling

I'm studying heat transfer from an electric heater to a cooking pan (Stainless steel) filled with water; specifically, my problem is related to water vaporisation, as I've already found good models to ...
3
votes
1answer
197 views

Sound waves creating bubbles in water

Sorry for the title, couldn't find a better one. A few years ago I read on a scientific magazine about a discovery, but I can't remember the name nor find anymore information on it. Basically they ...
0
votes
2answers
32 views

Increasing water temperature without salt

I have been extremely curious on how to get water even hotter by couple more degrees when its boiling. Rather then adding salt .... I started to stirring it.. Same Concept works with cooling the ...
5
votes
1answer
196 views

Why does a stream of water behave like this when aimed against a spoon or into a glass?

I noticed while doing everything except the dishes that water behaves quite strange. These two things might be two different phenomenon, but the water acts in a similar way in both cases. Spoon and ...
3
votes
2answers
74 views

Mirages under water?

In Polynesian shallow water, the temperature difference from short place to place is so high that one can see the same trouble refraction that exist in air above fire or metal sheet in summer. So I'm ...
0
votes
2answers
61 views

How much energy could be obtained by freezing water?

I know with our current technology energy is required to freeze water. But if the theories are correct we should be able to freeze water by extracting energy correct? How much energy could be ...
1
vote
0answers
25 views

Waterproof Case Time Limits [closed]

A lot of cellphone cases are rated safe for one hour at two meter depth. I assume this is due to water molecule diffusion along case seams (like the zipped zipper in a ziplock bag), right? Is ...
1
vote
0answers
89 views

standing waves on a cylindrical jet

as we know, there are some perturbations on a falling jet which are always present and according to their wave number and the radius of the jet, they can grow and decay over time. so, imagine a jet ...
1
vote
1answer
126 views

Can a hose filled with water go up if there is not a lot of pressure?

This might be more a general knowledge-type question or physics basics (or maybe not even physics) if so, I apologize and never took a physics class (my school never offered it), so I am not really ...
1
vote
1answer
53 views

Difference of water pressure

We know that $P = \rho gh$, so is it true that water pressure at 2nd floor will be higher than water pressure at 9th floor of a 12 story building?
2
votes
0answers
33 views

How fast does water have to be moving for it to gain a lot of heat? [duplicate]

A random question popped into my head a few minutes ago: objects, when moving fast enough, start to get resistance from the air. Since there is friction between the air and the object [water], there ...
0
votes
3answers
184 views

Why is alcohol less dense than water?

Ethyl alcohol (ethanol) is less dense than water, and it's boiling point is lower. But this molecule is more complex and bigger than the simple H2O. How can a substance with a higher molecular size ...
-1
votes
2answers
244 views

Torricelli's speed of efflux law

Torricelli's law states that if we make a hole in a container of fluid open to atmosphere, then the speed of the fluid spouting out is: $$\sqrt{2gh}$$ Does this velocity correspond to the horizontal ...
3
votes
0answers
46 views

What is the spheroidal temperature of water?

I understand that when a hot plate reaches a certain temperature water will no longer wet the surface, but will form perfect spheres on the surface of the plate. The temperature at which this happens ...
0
votes
1answer
79 views

Are particles that locally evaporate off water's surface at T = 100?

Water molecules can evaporate off a surface without needing to boil (How does water evaporate if it doesn't boil?). This is because surface particles are sometimes energetic enough to overcome ...
0
votes
0answers
32 views

Superheating Water Demonstration with a Vacuum

There are many Youtube videos which place a cup of water into a vacuum chamber and cause boiling around 0.020 atm, but I can't find any which show a vacuum-only "superheating" effect (to be clear, I ...
3
votes
2answers
134 views

Why water boiling time depends linearly on water volume?

I thought that the function will follow the Square-cube Law since we heat water at the surface (which is x^2) while we heat the volume (which is x^3) as it happens in animals according to Bergmann's ...
-1
votes
3answers
85 views

Velocity of water from a certain depth

I was curious to know does water come out of a certain depth when there is a difference in pressure, and also if it does come out of a certain depth, at what velocity does it travel at? So, ...
1
vote
1answer
86 views

What makes bathroom soap bars to crack during winter season?

Is there some relation between winter season and cracking of bathroom soaps? I noticed that , cracking happens only during winter season.I also learned earlier from physics stack that, During winter ...
3
votes
1answer
724 views

Why does sound not travel between media?

So imagine you're at the beach; you go into the water and the moment you enter the water you stop hearing anything from the outside world. The same happens vice-versa: your friend shouts at you from ...
0
votes
2answers
75 views

Why is water such a poor electromagnetic conductor? [closed]

1.-Why does salt water not conduct any form of non-visible light? 2.-Why does it conduct red light so much worse than other colours? (Why does it absorb red so much and not blue, for example). It's ...
2
votes
4answers
612 views

Better explanation of why an object floats: density? or buoyancy in equilibrium with object's weight?

Across StackExchange, you see two explanations for why an object floats: The buoyant force, equal to weight of displaced water, is in equilibrium with the object's weight. The density of the object ...
0
votes
1answer
35 views

Hydrostatic pressure in a vase at different depths

I am building a water level sensing device on the base of Arduino. The sensor is the eTape by Milontech. The resistance changes almost linearly with depth as the sensor is immersed in liquid (...
2
votes
2answers
139 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
vote
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
vote
1answer
109 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
votes
3answers
950 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?
1
vote
1answer
357 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 ...
0
votes
0answers
54 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
votes
1answer
31 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
88 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
votes
1answer
108 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
votes
3answers
126 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"
1
vote
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?
1
vote
0answers
106 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
55 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
34 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
94 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
88 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
448 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
votes
2answers
363 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
133 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
142 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?