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

learn more… | top users | synonyms

2
votes
2answers
164 views

If the MH370 black box did sink to 15000 ft, how long would it have taken?

I have been following MH370 on the news just as everyone and latest reports seem to indicate that the black-box could be found. A recent info-graphic http://t.co/lyBBE9C2hF shows the insurmountable ...
4
votes
0answers
21 views

Time for which a drop stays in the leidenfrost point

Is there any way to find out the time required for a drop of given dimensions to vaporize after attaining Leidenfrost point?
1
vote
1answer
67 views

Modeling Water Surface Impact

I have a project that is to model the wave equation in a pond due to a pebble being thrown in. The project is quite simple as all we really have to model is the wave equation with an initial ...
5
votes
3answers
210 views

Do hail stone fall down just when it is created?

Density of ice is much higher than air. Then how can hail stone remain in earth atmosphere before they fall down ?
29
votes
6answers
8k views

Why is jumping into water from high altitude fatal?

If I jump from an airplane straight positioned upright into the ocean, why is it the same as jumping straight on the ground? Water is a liquid as opposed to the ground, so I would expect that by ...
2
votes
1answer
84 views

Time taken in changing surface tension [closed]

I had read some where that the water in glasses has a high surface tension, but in lota (It is sort of a spherical container) the surface tension is lower. How can I measure the water surface ...
2
votes
0answers
85 views

Could water physically makeup the core of a planet or otherwise large celestial mass?

Knowing very little about the nature of water, wondering how it might behave at the centre of a planet or centre of an another massive gravitational body. Could water take such pressures or might it ...
0
votes
1answer
105 views

How does ice become thinner inside a no-frost fridge?

How does ice become thinner in a no-frost fridge? I thought ice can't evaporate at all since, well, it's below freezing temperature and it's solid, too. In my other yes-frost fridge, the ice never ...
23
votes
9answers
13k views

How can water evaporate at room temperature? [duplicate]

Boiling point of water is 100 degree Celsius. The temperature at which water in liquid form is converted into gaseous form. Then how it possible for water to evaporate at room temperature?
21
votes
4answers
50k views

How does water evaporate if it doesn't boil?

When the sun is out after a rain, I can see what appears to be steam rising off a wooden bridge nearby. I'm pretty sure this is water turning into a gas. However, I thought water had to reach 100 ...
1
vote
1answer
115 views

Different solutions for floating a DIY torii gate deeper than it's original floating level [closed]

I'm facing a dead end with my physics experience on a new build I am working on. Any help would be appreciated. Basic problem: I am trying to build a floating wooden Torii gate to be placed on water ...
4
votes
2answers
515 views

Why does my kettle only make a noise when it is turned on

Almost as soon as I turn my kettle on it starts to make the familiar kettle noise, yet very shortly after turning off the power the boiling noise stops and the kettle is totally silent. The ...
1
vote
2answers
2k views

Why does a bottle shrink when you pour hot water in it?

I think the title says pretty much. Last night I poured hot water in a half full bottle of water and closed the cap. The bottle immediately shrunk. Why? My girlfriend suggested that the hot water has ...
4
votes
2answers
121 views

The velocity of a cloud?

I noticed an unusually fast moving cloud this morning. My questions: What is the average velocity of a cloud on Earth? What is the greatest ever recorded cloud velocity? What factors affect the ...
12
votes
4answers
3k views

Thermodynamics of supercooled water

Now that it's been freezing outside for the last few days, I experimented a bit with supercooling. I've left a bottle of clean water outside for a few hours, and behold, when I shook the bottle, the ...
43
votes
4answers
4k views

Why is water clear?

Water appears transparent to visible light, yet most other objects are opaque. Why is that? Is there an explanation why water appears transparent? Is water transparent at all wavelengths, or are ...
4
votes
1answer
94 views

Is nuclear fusion via underwater vacuum possible?

An under water explosion creates a bubbly which quickly collapses on itself. The action takes less that 1/100 of a second for bubbles less than a foot across. This creates a point of extremely ...
4
votes
1answer
135 views

Water falling, why does it spin?

I have noticed that water, when falling will rotate. Looking closely at a thin stream from a faucet and placing a flat object mid stream you will see the water is rotating. The further down the stream ...
6
votes
2answers
356 views

Why does the gas cloud of an underwater gunshot pulse?

I have been watching some slow motion video and I was intrigued by the slow motion underwater gunshot. The first moments of the video go as expected. The gun fires and a cloud forms in front of the ...
0
votes
2answers
95 views

Why doesn't water start to boil in soils?

Consider the following two scenarios: I take a vessel filled with some water and evacuate the air, the water will (or rather can) start to boil; if the pressure in the vessel is << atmospheric ...
3
votes
1answer
113 views

Why is the water on one side of a bridge choppy?

My daily commute take me across the Evergreen Point Floating Bridge on Lake Washington. I have noticed on several occasions that the water on the southern side of the bridge will be quite choppy ...
1
vote
0answers
51 views

Why color of dress changes when water falls? [duplicate]

When you drop water to dress actually the color changes, that is the color of dress becomes dark, but when you add water to color, for example water color or poster color it becomes light. Why is it ...
7
votes
0answers
190 views

Ice cube left in water at 0 °C for a thousand years

Let's say we take an ideal calorimeter with a liter of water at +5 °C and throw a 5×5×5 cm cube of ice having temperature of –70 °C. I choose these initial parameters so that the stationary ...
2
votes
1answer
115 views

Continuity and Blood Flow

Consider a tube with two different diameters (one section wider than the other). Because what comes in must go out (conservation of mass), the flow rate in the wider section must be the same as the ...
0
votes
3answers
413 views

Using water to amplify sound

It seems that water generally dampens sound waves. Is there any way one could attach a speaker to a body of water in such a way that the water would actually amplify some frequencies (for nearby ...
1
vote
1answer
167 views

Why does a bucket of Water weigh more than a bucket of Air?

Given the numerous chemical compounds found in dry air [compressed into a liquid] of a given volume [lets say $22.4$ L for simplicities sake] whose atomic weights far surpass that of water alone ...
3
votes
3answers
416 views

Water Level and Pipe Widths

I ran into a bit of physics yesterday, and couldn't understand the physics at work. I've been scouring the Internet, but haven't found the answer yet. I'm guessing there's a basic principle I'm ...
0
votes
3answers
117 views

Raindrops on a fence. Why a regular pattern?

I observed a fence composed of plastic-coated metal wires running vertically and horizontally at intervals of around 3 cm. After it had rained, drops of water remained on the horizontal wires. I was ...
21
votes
4answers
524 views

Why is lightning more rare during snow storms than rain storms?

Lightning and thunder during a snow storm is uncommon. As far as I know, more uncommon than during a typical rain storm. Why is this? I speculate it might be one, or both, of the following two ...
1
vote
2answers
98 views

Should water cool faster if is inserted metal canister with ice inside either mix only with ice?

Let's say that we have two canister first bigger (metal canister 2l) with 1l of water at 100C, and second smaller (metal canister 1l) with 1l of ice. And we want to cool down boiled water to 50C. So ...
0
votes
2answers
459 views

Compression and expansion

Why is it that solids on compression [As in striking a hammer etc.] heat up, but liquids and gases on compression [Pressurizing liquids causes them to freeze or gases to liquify] cool down? Can ...
-2
votes
2answers
166 views

If a planet were cut in half but stayed hemispherical, how hot would the ocean on the flat side be? [closed]

Some time ago I asked a question about gravity on a hemispherical planet. What would gravity be like on a hemispherical planet? Would the water all boil away at first, quickly cooling the core of ...
3
votes
1answer
41 views

What is the equivalent of a eutectic point for a (two-liquid)+solids system?

I deal with complex phase equilibria involving solid and liquid phases at high temperature. Below is a simplified temperature-XH2O diagram for a multicomponent system at constant pressure. (Note: ...
0
votes
0answers
22 views

Building a magnetron powered steamer

I am wanting to build a microwave powered steamer for a reverse engineering project in university. I've read up some on this and know that its not as efficient as a heating element. I'm curious about ...
2
votes
3answers
271 views

How much energy needed to push a volume of water?

I am trying to solve a situation, where I'd like to know how much energy would be needed to push a mass of water out of a container. Here's an image to help understand: The water tank has a height ...
0
votes
3answers
106 views

cooling glass of milk glass and a jar of water

When im given a steel glass of boiling milk which I cannot even touch, I used to put that glass in a jar surrounded with room-temp water and give it 10 mins. At the end, I used to find the steel glass ...
5
votes
1answer
64 views

What are circles on broth (eating soup) surface?

Think about broth in the soup, usually it has circles on its surface. What are their properties? Why there are many of them (not a few big blobs)? Are they depended on liquid's temperature? What needs ...
4
votes
2answers
7k views

Flow of liquid among branches

If water is flowing through big pipe is branched into 4 branches of small pipe. Lets say the flow is around 4 m/sec. I have the following questions: What will be the flow rate in each of the ...
4
votes
2answers
66 views

Why water vapour condense easier in contact with a solid?

Reading about cloud formation, I learned that to a droplet to form, the water vapour needs a Cloud Condensation Nuclei, which is an aerosol with a size in the order of 0.0001mm. And if no CCN is found ...
3
votes
2answers
1k views

Why doesn't the water spill out?

In this experiment, a number of coins are put into a cup full of water, without spilling it. http://www.youtube.com/watch?v=N2mKpZHnEzw Firstly, let me clarify one thing. If you fill up a cup ...
8
votes
2answers
351 views

How to model the form of a surface water wave?

Normal surface water waves, as generated by wind, do not have sine form but wave peak is higher and shorter than wave trough with different wave steepness. What parameters characterize such a surface ...
3
votes
1answer
2k views

Where are the ice rings in X-ray crystallography located?

I threw this image of one of my protein crystal's diffraction pattern (not the greatest) on a poster, and was wondering where (what reciprocal dimension) the ice rings are located as it might be a ...
44
votes
4answers
4k views

Being in a solid state, why is ice slippery? [duplicate]

Saying that ice is slippery is like saying that water is wet -- it's something we've known for as long as we can be said to have known anything. Presumably, humans as a species knew ice was slippery ...
2
votes
2answers
314 views

Would sea water moderate a nuclear submarine meltdown?

My son asked me: If nuclear submarines get sunk or blown up, what is to stop them going into nuclear meltdown? I thought about it and came to the conclusion that because they're in the sea the ...
0
votes
0answers
87 views

Determining The Coefficient of Viscosity and Diffusivity in an Estuary?

I am curious and eager to discuss about the experience of determining viscosity and diffusivity coefficient for our coastal or estuary model. I myself, just start to use the range of: ...
1
vote
2answers
133 views

What is a good model for computing water dropping on a surface?

Before introducing my question I would like to outline the fact that I'm a coder, so I can be wrong when using some kind of terminology. What is a good model for computing the flow, the shape and all ...
4
votes
2answers
128 views

Dynamics of Honey in hot water: Honey accelerates like it is falling through air?

Here is a Video showing the honey accelerating in the hot water. As you can see, there are also dynamics. Since the water started stationary, I guess the dynamics arise because of convection flow. ...
17
votes
6answers
4k views

Why does ice form on bridges even if the temperature is above freezing?

So with this "arctic blast" continuing, I've noticed that for my area, the temperature drops below freezing just long enough to cause freezing rain, but then the sun comes out and the temperature ...
-3
votes
1answer
127 views

Slope of a channel

I have a trapezoidal channel like this: The question is to get the slope of the channel such that we have a Chézy coefficient of 64 $m^{1/2}/s$. Given: $B= 76\: \mathrm{m}$, $y = 10\: ...
0
votes
3answers
489 views

Why are oxygen and hydrogen compressible, but water is barely compressible

What makes the two gases compressible, but does not apply to a liquid like water?