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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4
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2answers
126 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
1answer
15 views

How quickly does the temperature rise in a water container submerged in a hot water bath?

Let's assume I have a small bottle (neglecting any insulation from the walls of the bottle) containing e.g. 150ml water at 4°C and place it in a larger pot with sufficient water at 80°C so that the ...
6
votes
1answer
465 views

Calculation of water bulk modulus using equation of state

I simply want to calculate the bulk modulus of water at 50C and increasing pressures. I think I am correctly calculating the new specific volume from the original conditions at (25C and 1atm) to 50C ...
0
votes
0answers
22 views

Water volume vs. pressure [on hold]

I have a pump that can deliver 14000 liter per hour. It is rated for a lift of 6m and a push of 36m. It has a 4m long 25mm hose as inlet(fed from a 30,0000l tank) and a 25mm outlet connected to 2m ...
1
vote
1answer
220 views

Does the termination point(level) influence water flow from a pipe

I get water to my home from a nearby Tank A at a certain height above ground level. I have a 1" pipe through which I get this water to my home.. I leave this water into my well by connecting a 1" tube ...
1
vote
4answers
94 views

The impatient hot tub owner [on hold]

An impatient man owns a 300 gallon hot tub. He comes home from a hard day of work and sees that his hot tub is currently simmering at 90F. For maximum relaxation, he wants it at 104F. However, the hot ...
1
vote
2answers
57 views

Does shaking a kettle whilst boiling increase the temperature faster than a statically-placed jug?

Water molecules move faster at higher temperatures. Does shaking a boiling kettle whilst it is in the process of boiling water increase the rate of rising temperature ? Is it worthwhile to do so ...
0
votes
2answers
244 views

Will an object with a higher temperature lose its heat faster than a cooler, yet warm object

I'm after the math, which I don't understand yet and can't find elsewhere. The variables are: Two identical cups, A and B The same volume of fluid is contained in each cup, test fluid is water. ...
0
votes
1answer
46 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
167 views

Does water diffuse trough rubber of car tire of when liquid or only as gas

Does Water difuse trough rubber of car tire when its liquid or only when its a gas. Can also be that is diffuses but slower when liqiud. I want to know this for my argumentation that filling car tire ...
7
votes
3answers
642 views

Why is salt so hard to remove from water?

Water molecules and various salt molecules are very different. However, it seems very difficult to separate the two. Once a salt is dissolved in water, an energy or chemical intensive method (like ...
4
votes
1answer
3k views

Do my noodles cook quicker when the water is boiling or when it is just about to boil?

I was just cooking some noodles and staring at the pot waiting for them to cook made me wonder... Will my food cook quicker when the water is boiling and bubbling, or when it is at a temperature where ...
0
votes
0answers
9 views

Is there a relationship between maximum flow rate of a fluid through perforations in a cavity and the flow rate of the fluid in the cavity itself?

I have a scenario where water is flowing horizontally through a (rectangular) cavity. The underside of the cavity has a set of perforations that look something like: and I need to determine the ...
3
votes
2answers
529 views

Water Waves in the Wake of a Boat

As a boy I noticed that the waves from the wake of my model boat would fan out. If I looked at the end furthest from the boat the front had turned so that it was almost running in the same direction ...
3
votes
3answers
270 views

Effect of initial suction power on siphon performance

Background I have a flooded crawl space and I'm using a long hose to siphon the water out. I do this as follows: One side of the hose is in the crawl space, and the other side down a hill in the ...
0
votes
0answers
33 views

Can 1km diameter ball of water preserve it's integrity before hitting the ground falling from 10km altitude?

I still argue with my friend over some big ball of water (1km in diameter) that is being instantly created 10km over the surface of the earth in perfect sphere form. I stated, that as it hit the Earth ...
3
votes
1answer
49 views

A model for constant temperature of water in a container

I put some water in a container with initial temperature $T_0$ in a room, and the room's initial temperature is $T_a$. Now the container is filled to the maximum, so any more water coming in will ...
1
vote
1answer
52 views

How does water at different temperatures behave when they are mixed? [closed]

If I were to inject a constant flow of water at T1 into a reservoir of water at T2, how does that effect the temperature of the mixture at different points in the reservoir? In other words, what ...
30
votes
2answers
11k views

Why is boiling water loud, then quiet?

Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was ...
2
votes
2answers
64 views

Are raindrops actually “shaped like tears” when they fall?

Raindrops are always pictured like this, people imagine they have this shape when they fall, but is this true? Doesn't this shape create too much drag? What shape do they really have? It would also be ...
2
votes
0answers
23 views

Does a rapid temperature change crack annealed glass [closed]

Over at Lifehacks.SE there is a question about how to remove ice from a windshield. One answer suggests using water but warns that using boiling water might crack the windshield. As far as I ...
0
votes
1answer
67 views

Using water pressure as pushing force [closed]

Is the process shown in this cartoon theoretically possible? What formula can prove this? (backup link 1, backup link 2) May be there must be very small hole in boat? Or a huge atmosphere ...
0
votes
1answer
33 views

Stiffness in water

How do I find the stiffness or Fluid Elasticity for water (at a given temperature of for example 40 degrees)?
1
vote
1answer
851 views

A water balloon in vacuum: does it boil?

If I put water in a vacuum it will boil. But what if I put this water inside a balloon ? I searched for answers and fount this video: http://www.youtube.com/watch?v=9q8F3ClUuV0 It seams that the ...
1
vote
0answers
12 views

Fermi estimate for ice nucleation timescale

My friends in a Cryo-EM lab freeze their very samples quickly, a process they call vitrification. The timescale for this process is milliseconds (from wikipedia): The production of amorphous ice ...
3
votes
1answer
264 views

Fluid dynamics tsunami

I have been given a energy head (pressure) in meters for a given tsunami on land. If the tsunami hits a wall 1 meter by 1 meter, is it possible to calculate the height it will reach. I am thinking it ...
3
votes
1answer
131 views

Why do liquids form less bubbles when poured at an angle?

For example, I noticed that when I pour a soda on the side of a glass instead of directly into the cup, it forms less bubbles. This is also evident with rootbeer floats. Is this an actual scientific ...
1
vote
0answers
23 views

Do (or can) hydrogen bonds between water molecules neutralize their own polarity? [closed]

Do (or can) hydrogen bonds between water molecules neutralize their own polarity as indicated here: Hydrogen bonding as the mechanism that neutralizes $\mathrm{H_2 O}$ polarity ...
6
votes
2answers
137 views

Why does warm water sink?

It is well known that water at 4C is denser than water at 0C. This is the usual explanation for why a body of water freezes from the surface (also it's because ice is even less dense, but that's ...
0
votes
1answer
161 views

What is characteristic time in Fourier number exactly?

What is characteristic time in Fourier number? How can I calculate characteristic time? Suppose I started heating water in a closed container by immersion rod and temperature increases ...
3
votes
3answers
36k views

Explanation for different boiling points of water on different altitudes

I understand water boils at different temperatures depending on altitude. I am seeking to get an illustrative explanation for this, including a diagram if possible.
0
votes
1answer
30 views

How can condensation be aided?

I was wondering if certain factors of water vapor condensation can be aided? For example, being able to increase the saturation of water vapor via a certain method, or another example would be having ...
0
votes
1answer
23 views

How can we use conductivity measurements of water to find hydrogen ion concentration of water?

How can we use conductivity measurements of water to find the hydrogen ion ($\mathrm{H}^+$) concentration in water?
2
votes
0answers
52 views

How does one determine the probability of $\mathrm H^+$ to $\mathrm{H_2O}$ in pure water? [migrated]

The ratio of $\mathrm{H}^+$ to $\mathrm{H_2O}$ is something around $10^{-8}$. How did people determine that? You cannot use the Kw, pH, [H+] ion concentration value to answer because you get all that ...
1
vote
0answers
34 views

Why does liquid flow along the mug [duplicate]

I have been wondering why situation described in the picture below happens Why does the water/milk or any liquid poured from the mug/bottle flow along the surface of the vessel instead of leaving it ...
2
votes
1answer
384 views

Equilibrium between two water tanks

I've been reading about hydrostatic theory, however I couldn't find a similar case/exercise about my basic problem. I have two water tanks (same size) filled with different water heights, and ...
0
votes
1answer
438 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 ...
3
votes
1answer
386 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 ...
7
votes
4answers
4k views

Effect of water pressure on sinking objects

As I understand, water pressure increases as we go towards bottom of the ocean. So if an object* is thrown into water and it starts sinking with some speed, does the sinking object's acceleration ...
8
votes
2answers
625 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 ...
2
votes
2answers
610 views

Dynamic water pressure from flow and diameter

I have to test some fire hydrants and need to get the dynamic pressure. For that I know I can use a Pitot tube but, I don't have one. After Googling a lot, I found two formulas allowing to compute the ...
1
vote
1answer
35 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
0answers
32 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 ...
3
votes
1answer
212 views

Force field for calcium ions, potassium ions and water in molecular dynamics

I want to adapt my existing MD simulation so that it can handle these three species. For the interactions of the ions I thought that I would use the coulomb potential, but I don't know what sort of ...
1
vote
1answer
68 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
40 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 ...
3
votes
1answer
160 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 ...
2
votes
6answers
16k views

Water pressure calculation for a volume of water at a given height

I'm looking to create a rain harvesting system. I have a 275 gallon IBC tote that is 48" x 40" x 46". I have an adapter for a 3/4 garden hose at the bottom of the IBC tote. I'm trying to figure out ...
1
vote
2answers
52 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 ...
6
votes
3answers
5k views

What is the resonant frequency of liquid water?

I learned it's not 2.45 GHz. But what is it, then? In my failure to find the real value, I'm starting to wonder: does it even make sense talking about a resonant frequency of water molecules?