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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1answer
22 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 ...
1
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2answers
2k 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 ...
0
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0answers
13 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? ...
0
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1answer
109 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, ...
0
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2answers
77 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.
3
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3answers
20k 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.
10
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3answers
5k views

273 + degree Celsius = Kelvin. Why 273?

Temperature conversion: 273 + degree Celsius = Kelvin Actually why is that 273? How does one come up with this? My teacher mentioned Gann's law (not sure if this is the one) but I couldn't find ...
0
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0answers
38 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 ...
2
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0answers
30 views

Can we prevent metal corrosion by creating a vacuum around it? [migrated]

I have a device in a box which has parts of metal. So can I prevent corrosion by creating a vacuum around the metallic object?
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2answers
79 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 ...
1
vote
1answer
162 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 ...
3
votes
1answer
129 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 ...
7
votes
1answer
609 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 ...
2
votes
1answer
46 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?
5
votes
1answer
530 views

Finding Surface Tension of water at certain Temperature and Pressure

The question is: Using the Young-Laplace Equation (if applicable), find the surface tension (dynes/cm) for water at 20 degrees Celsius with 2.5 psi. Round to the nearest tenth. ...
13
votes
4answers
18k views

Does wrapping a wet paper towel around a glass bottle really speed up the cooling process?

There are claims like this one that you can improve the cooling speed of beverages when you put them wrapped in a wet paper towel inside the refrigerator/freezer. I've just tried it by myself and ...
5
votes
4answers
664 views

Is there a depth at which a human body, with lungs full of air, will no longer float?

I was watching a special on divers who dove down hundreds of feet without tanks or gear. The show referred to a depth at which the diver was no longer buoyant and would actually sink, even with lungs ...
1
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1answer
30 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 ...
1
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0answers
22 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
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1answer
25 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?
-1
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0answers
20 views

In the Leidenfrost effect why droplets flow upwards

Leidenfrost effect is a physical phenomenon when a hotter liquid when it comes to contact with another significantly hotter body then the liquid creates a vapor layer and the liquid flows.Now why when ...
0
votes
3answers
191 views

Why are some surfaces slippery?

Why are ice and oil slippery? In general, why do certain substances make a surface difficult to walk on?
3
votes
2answers
743 views

Why do my ice cubes stick together? [duplicate]

When I put ice cubes in a glass of water, I find that sometimes they will stick together and form a sort of "bridge" between them as they melt. There is usually a visible line where one ends and the ...
0
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0answers
25 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
25 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 ...
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2answers
4k views

Is water considered a substance with low friction or high friction?

Like, for example, rubber is a substance with high friction, as an object with neither high or low friction would easily stop on it, and wouldn't skid. Ice is considered an object with low friction, ...
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2answers
22 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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2answers
3k 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 ...
3
votes
2answers
108 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 ...
1
vote
1answer
82 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
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2answers
158 views

Dielectric constant of water

I need the dielectric constant of water from $10^{-2}$ Hz to $10^4$ Hz. As stupid as it may seem, I cannot find much info. I've googled for days. All I can find is close to GHz. And the only info ...
1
vote
1answer
23 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 ...
0
votes
1answer
8k views

Water Electrolysis Calculations

From Wikipedia (http://en.wikipedia.org/wiki/Water_electrolysis#Efficiency): The electrolysis of water requires a minimum of 237.13 kJ of electrical energy input to dissociate each mole. Each ...
26
votes
5answers
5k views

Why does wet skin sunburn faster?

There is a popular belief that wet skin burns or tans faster. However, I've never heard a believable explanation of why this happens. The best explanation I've heard is that the water droplets on the ...
2
votes
1answer
132 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 ...
4
votes
3answers
70 views

Why does the light reflecting off of ocean water sometimes appear 'smoother'?

Looking out the window at some water in the Harbour - I noticed that some parts of the water appear 'smoother' than others. My question is: Why does the light reflecting off of ocean water ...
17
votes
1answer
678 views

Could there be a body of water the size of a planet?

My friend and I were reading the news of the discovery of a black hole spewing huge amounts of water vapor into space, and it got us thinking: could there be a blob of liquid water in space the size ...
2
votes
3answers
930 views

Could submarine SONAR kill a diver?

Could a diver swimming next to a submarine be killed or seriously injured by its SONAR? What physical aspect of SONAR affects the human body in a potential harmful way?
2
votes
2answers
252 views

Dynamic water pressure from flow and diameter

I've 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. After Googling a lot, I found two formulas allowing to compute the ...
0
votes
0answers
13 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 ...
-2
votes
1answer
83 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 ...
0
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3answers
108 views

What could be added to tap water to reduce air bubble formation on a submerged object?

Submerge your hand in a bucket of water. Some air bubbles appear immediately and others add to the surface of the hand over time. Is there anything that could be added to the water to reduce the ...
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
29 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.
5
votes
1answer
123 views

What would happen to a submarine coated in water repellent

I saw the article about laser-etched hydrophobic metal, and it got me thinking, how would a submarine function differently if coated as such? Would it move faster, sink completely, be unable to move ...
1
vote
4answers
183 views

Why does a metal boat float?

I was in class learning about density and stuff. Our teacher told us that things that are denser than water sink in water, and less dense things float. Then, our teacher asked us why metal boats ...
6
votes
7answers
11k views

Why does hot oil explode when pouring water on it?

I am puzzled to know, What is the reason of hot oil make sound and explode when we pouring water on it?
0
votes
2answers
57 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 ...
1
vote
1answer
34 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
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1answer
42 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?