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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14 views

Where are real limits of evaporative cooling?

There are many projects focused on utilising evaporative cooling for food preservation or computer cooling purposes. I have other thing in mind, however and that's cooling beer. Once you're outside, ...
9
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0answers
2k views

How to keep a bucket of water from freezing by only natural means? [migrated]

Strange question. I am working on a fictional story where a person has to carry a bucket of water for hours during a blizzard. Is there any natural way to keep a bucket of water from turning to ice in ...
0
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2answers
57 views

How fast will 1 Liter of 65°C water get back to 20°C?

I want to make a very simple example for a PID controller (to learn and understand it). I thought of a controller for a water boiler. 1 liter of water in the boiler is in a 20°C room (fixed ...
0
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1answer
34 views

Is it possible to create helium atoms by bombarding heavy water with neutrons?

If heavy water is bombarded by neutrons is it possible that any of the deuterium atoms can capture neutrons and transmute to helium atoms? I suspect the more probable event would be knocking protons ...
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3answers
58 views

Feasible way to cool water (ice) to temperatures around -20 degree celsius

Is there an easy way to cool water to temperatures around -20 or -30 degree celsius that is economically and technologically feasible for a high school student. Can it be done using typical household ...
8
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1answer
1k views

Water in a vacuum sealed jar?

I recently purchased a Vacmaster VP215C chamber sealer, and have noticed that when I place a small container of water into the chamber, and pull a vacuum for just over 25 seconds, the water begins to ...
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1answer
40 views
4
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2answers
18 views

How to find the maximum area of a slot that can keep water in a trough by surface tension?

Assume I have a trough of water 5mm deep. If I cut a slot (oval) into that trough what is the maximum size/area (length x width) that slot can be without leaking? This question is similar to Max. ...
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1answer
64 views

Properties of a star made from water? [closed]

What would the properties of a star formed from a sphere a water/ice be? One large (massive) enough to collapse into an ordinary, mostly plasma star. I understand that it would have particularly high ...
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2answers
15 views

Why bigger stream of water in a metal sink is more silent than a smaller one?

I have a metal sink. I don't want to waste much water so I prefer smaller streams of water. But when the stream is small it makes a big noise. However, when I increase the flow, the tapping sound ...
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2answers
47 views

What could be the effects of accidentally spilling supercooled water/liquid on an unprotected body surface?

Will the body rapidly start losing heat or will the water find a seed and solidify around it ?
0
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1answer
29 views

What is characteristic time in Fourier number exactly?

Please tell me 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 ...
0
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0answers
35 views

Why is there steam in a hot shower even though the water is not boiling?

When I take a hot shower, there is normally a fair amount of steam. However, I don't think the water coming out of the shower-head is actually boiling (unless I am mistaken). Why is there water ...
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0answers
28 views

water is dropping from car? [migrated]

I bought a car yesterday Nissan 2009 , today i have noticed that water is dropping under the front passenger seat.is there any one knows what is the problem please.
0
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2answers
46 views

Will going up with a larger diameter ensure a higher water pressure in the distribution pipes? [closed]

Have a look at the drawing below describing a sample situation: a water tank a 1'' diameter pipe bringing the water down, inside the ground, arriving near the house in the house, 2 x 0.5'' diameter ...
1
vote
1answer
28 views

what force pump is needed to power [closed]

Im studying design have not got a good grasp on maths, but understand the working principles of pressure and water! my problem hopefully has included all necessary info in the image. Please help. ...
0
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1answer
30 views

can ice crystals be molded into a structural shape in space

I know that water exposed to vacuum space first boils and then turn into vapor (sublimates) . Is it possible re use this vapor say inside a pressurized membrane, to mold it into a solid ice structure, ...
0
votes
1answer
64 views

Is possible to create water? [closed]

Theoretically is relatively easy to create water, because it is formed by only the hydrogen and one oxygen molecules. I know that the oxygen and hydrogen is highly flammable, and to union the ...
0
votes
4answers
55 views

What is the state of water at exactly 0°C?

Theoretically speaking, what is the state of water at bang on 0°C - not any lower or higher? Any lower would make it a solid whereas any higher would make it a liquid. But what about bang on 0°C? ...
3
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2answers
32 views

Air bubbles in Ice and cause for their shape?

I was looking at the ice formed in my refrigerator and found out there were a lot of air bubbles inside it. The shape of the air pockets seemed strange to me. There were many small spherical ones ...
3
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1answer
35 views

What mechanism creates bubbles in water that stays awhile

If I fill glass jar with tap water and let it stay, small bubbles will appear on the side of jar after a while. I am wondering what processes create those bubbles and what conditions require to ...
0
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1answer
42 views

Why is the melting point of an object inversly proportional to pressure?

In my science book it is written that as the pressure increases the melting point of a solid decreases but i think that it is wrong as the pessure will make the molecules stick together instead of ...
0
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3answers
47 views

Can we create plasma with other things except gas?

In my school book its written on how plasma is created and it is said that we can create plasma by ionizing a gas but i have heard that plasma can be created even from liquids like water and also from ...
3
votes
2answers
94 views

What is the maximum net force of surface tension per gram of water?

I've always wondered how much force water exerted through surface tension. By maximum I mean the theoretical pulling/attracting power. Also, what would happen if you raised or lowered the power? ...
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2answers
86 views

Which one is colder? Zero temperature ice or zero temperature water?

I like to understand that which one of the following items seems colder, when we touch them? zero temperature ice zero temperature water Why? Thank you.
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0answers
43 views

How much water is needed for Saturn to float in?

Saturn floats because it's density is less than that of water. Just how much water would be needed? Assume a cuboid tank holding it. And when we actually put saturn in that water, how far in the ...
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2answers
128 views

How long does it take for water to boil when subjected to intense heat?

I have a rather odd question that may just boil (sorry) down to a fairly simple problem I can't solve. The scenario is this: A person is testing the intensity of a super-focused beam of sunlight in a ...
3
votes
1answer
85 views

Why does paper become uneven when soaked and dried?

Pouring water on a small part of sheet of paper and then drying it makes it uneven, it gets a wave like appearance and seems to have become larger in size. Why?
1
vote
1answer
32 views

Is it possible to send modulated ultrasound wave from underwater to air?

Is it possible to send modulated ultrasound wave from underwater to air? In case of radio frequency it is refraction loss at the surface between water and air. Is it something similar for ultrasound ...
7
votes
1answer
625 views

Why when I put a teabag into microwaved water does the water fizz? [duplicate]

When I am in a rush, I will heat up water in a cup in the microwave for tea. I usually put the cup on high for 2 mins. When I put the teabag in, the water starts to fizz almost like it is ...
1
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0answers
33 views

Electrical conductivity of pool water [closed]

What is the electrical conductivity of pool water? I tried to find some information, unfortunately with no success. I need to know it to make an underwater electronic project. Thanks
-1
votes
1answer
30 views

Water and steam ratio

What is the relationship between the water and steam? I've read that 1 mililiter of water evaporate to 1.6 LITER of steam. Is that true?
0
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0answers
32 views

What will be the final temperature of water when heating at a a rate 10J/s?

If I supply heat of rate 10W to water of mass 250g and initial temperature of water is 29 degC then what will be the final temperature of water when steady state is reached. **Water is heating in open ...
0
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0answers
27 views

Water as heat source in a heat pump

Consider we have water flowing in a pipe, which is working as a hot source for a heat pump. We are able to know the temperature of the water in both ends of the pipe, yet we don't have information ...
-1
votes
2answers
30 views

Conservation of Sea water Vs Conservation of Matter

I have been listening to people, since my childhood, saying that amount of water in Sea always remains constant even if we draw out much from it, it never changes. They used to emphasize by saying ...
1
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1answer
34 views

How does water pressure manifest itself on the molecular level?

Second, related question: does water density relate to, or cause, water pressure? Everyone I talk to dismisses the idea that water density substantially affects pressure, and emphasizes that water is ...
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0answers
17 views

How much temperature reduction can we expect when pouring water into the cup from an elevated kettle?

Turns out some people who are into green tea use the following technique to cool the water from the kettle down. They lift the kettle and pour a rather thin stream of water in the cup. Because of high ...
-1
votes
1answer
95 views

How to heat water to 80°C? [closed]

I'm trying to figure out an easy water to get 80°c to consistently make the perfect cup of coffee. Let's assume room temperature water is 22°c. What is the ratio of boiling water to room temp water ...
2
votes
2answers
140 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 ...
8
votes
4answers
2k views

A cup of water in ZERO gravity

What will happen if I try to pour a cup of water in zero gravity, into another empty cup? Will the water come out of the cup? The adhesive force between the water molecules and the interior of the cup ...
0
votes
1answer
30 views

High pitched noise as hot object hits water?

https://www.youtube.com/watch?v=9qSEfcIfYbw Just wondering what this phenomenon was called, and its cause? Would have googled, but I don't even know what it's called.
1
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1answer
40 views

How does water-soluble packaging work?

Recently, I have been using detergent tablets in a water-soluble package for my dishwasher. How does the packaging get dissolved in water?
4
votes
1answer
81 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?
0
votes
1answer
118 views

If we dropped an object into the Pacific Ocean, would it completely sink to the bottom of the ocean floor or not?

Obviously if the density of the object is smaller than the density of water it would not sink at all. But I was thinking that, even if the density of the object is greater than the density of water, ...
2
votes
1answer
33 views

Does humidity affect passage of microwaves?

Does the humidity level in air affect the passage of microwaves? I've heard people say water is radio opaque, so could a high humidity level lead to faster signal degradation? As an example, would ...
1
vote
0answers
36 views

How water anomalies affects the Mpemba effect?

I understand basic explanation of Mpemba effect like this: Distant molecules are easier to realign into new formations. But if we compared two bottles of water like in Mpemba effect and one of them ...
0
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2answers
67 views

hydrostatic pressure on a plane surface

I've been trying to calculate the amount of pressure on a wall of a rectangular structure, that is under sea watter. For example a dam. I can't come to see any example to be able to locate the ...
0
votes
0answers
17 views

watter remaining liquid in low temperatures

On several occasions I have witnessed the following phenomenon and would like to understand the physics behind it: Water is placed in a very cold static location, in a cup or plastic bottle in a car ...
0
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0answers
31 views

An interesting question on the mass of a droplet of liquid experiencing the Leidenfrost Effect

Background and Inspiration: I have seen numerous demonstrations of the leidenfrost effect, both on the internet and in my mother's kitchen. But I started wondering about a general case after having a ...
6
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2answers
631 views

Is it possible to disprove water memory with an entropy argument?

Water memory was a controversial experiment claiming to provide an explanation supporting homeopathy. The results were largely dismissed as being tainted by experimental error. One possible mechanism ...