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Questions tagged [water]

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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Is light penetration through water affected by water pressure?

Does water pressure affect propagation of light through water?
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73 views

Thermodynamics trick question [closed]

My professor mentioned this in class as something to think about, but I can't figure it out. The riddle goes: If a bucket of water is standing in a shop window where the sunlight shines through, ...
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1answer
62 views

Is the triple point of water exactly 0.01 $\deg$C?

Is the triple point of water exactly $0.01 \deg$C, or is this an empirical value/is there some uncertainty to it? If so, how do we know it is exact, and why?
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1answer
24 views

What is role of nucleation centre in the formation of ice?

Water must be impure so that the impurities can act as nucleation centre for ice to form. What is role of nucleation centre? Why can not ice form with some nucleation centre.
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2answers
68 views

Temperature of items from a freezer [duplicate]

I've read that all items in a freezer are at the temperature at which the freezer are set to (obviously items have to be in the freezer long enough). So, if I put normal tap water in a freezer which ...
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2answers
95 views

Which one is better to boil water, using high heat or less heat?

Consider that I have a water boiling kettle as below. Assume that it is made of metal, not plastic (but plastic probably also will do). Assuming I can adjust the power it uses to boil the water with ...
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3answers
458 views

Why does sound behave differently in water than in air?

I noticed in some experiments at home that sound does not behave the same in water than in air. Is there a good scientific explanation to this? I noticed that the sound sounded distorted in water but ...
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0answers
11 views

Why is water attracted by static electricity and not repelled? [duplicate]

As most of you will certainly know, when a statically charged object is put close to a stream of water, the stream of water bends towards the charged object. Gathering information online, it seems ...
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4answers
2k views

Why do ice crystals form from the top to the bottom of a bottle filled with supercooled water?

If I bang a bottle filled with supercooled water against a hard surface, the ice crystals form from the top to the bottom:$\hspace{50px}$$\hspace{75px}$–source. YouTube has videos showing this ...
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1answer
39 views

Is it possible to drain all oceans' water to space? [duplicate]

Assuming: That I have an ideal straw (a very long pipe) from the ocean to space; That the straw (pipe) is ideal (will not break); That i can pump all the air from the pipe creating vacuum inside the ...
3
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0answers
22 views

Sound emitted by droplets hitting a liquid surface

when a liquid jet (e.g. water) hits a water surface sound may be produced if, due to Plateau Rayleigh instability, the water jet has formed into droplets. But what exactly causes the sound? Is it the ...
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2answers
142 views

Is it possible to have a planet entirely made out of liquid water?

Earth is mostly covered in oceans, but they only go a few kilometres deep. It's obviously not possible to have a planet the size of the earth to be made entirely out of water, because of the kind of ...
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1answer
38 views

How can one the find normal force of a block resting on a pool floor underwater?

There is the force of gravity on the block, the atmosphere, the water pressure o top of the block, but how about between the block and the floor? Would we calculate water pressure pushing up from the ...
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2answers
46 views

Why does air get trapped below water pouring into a glass?

The drinking-water-tap at my workplace has a low pressure continuous stream of water. When I pour water into a glass which has at least about (depth) 5cm of water in it, surprisingly large air bubbles ...
1
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1answer
44 views

Laminar Flow From Outdoor Faucet

I ran across a video recently that really caught my attention. It's been circling the internet over the past couple weeks, but I'm trying to figure out what's going on. Basically, it's a video of an ...
2
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3answers
56 views

water pipes break when temperature goes down, how to estimate the energy involved?

Normally low temperature is associated with lower energy state and high temperature with higher energy state. There is an apparent paradox when a water pipe breaks due to low temperature: when ...
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0answers
15 views

Is there any equation to calculate water vapor condensation?

Basically, I can to calculate the mass of water accumulated on a surface at a given time if the surface is exposed to Room temperature keeping its temperature let say -25 C. Any help will be ...
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1answer
19 views

Charge density of sea water

If sea water contains salt ions and some H+ and OH- ions, what are the charge density of a certain volume of sea water? And is there a way to calculate?
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1answer
44 views

How do salt crystals evaporate in water?

Salt dissolves in water but when water has evaporated it is still there. What has happened to the salt in the water and why is it still there when water has evaporated?
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1answer
37 views

Water / Air flow via thermal difference

This is a simple water/air flow thought experiment I had that I'd like to understand better... The basic idea is that you have a closed loop of water or air standing vertically. One side is heated to ...
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3answers
50 views

What am I doing wrong in electrolysis of water?

I am trying to two 1.5V battery in series to electrolysis a small bowl of tap water oversaturated with salt. But I can't see any bubble on the part submerged (circled on the photo). Could you guys ...
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1answer
19 views

Will water spill out of filled capillary tube, if raised from water?

if to raise a filled capillary tube from the level of water, will the inside will spill out? or will it keep stuck inside? imagine a capillary tube put in water, the water rises inside the capillary ...
18
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4answers
2k views

Why are we able to see air bubbles under water?

Title is self explanatory. I'm assuming both water and air are transparent. So, if they are true, how can I clearly distinguish an air bubble under water?
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4answers
6k views

Why doesn't water actually perfectly wet glass?

According to many high school textbook sources, water perfectly wets glass. That is, the adhesion between water and glass is so strong that it is energetically favorable for a drop of water on glass ...
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3answers
6k views

Why does a lot of water vapour come suddenly after the heat source of boiling water is removed? [duplicate]

I have noticed this several times. When I am boiling water, a few seconds before its boiling point, vapours are formed as usual. But if I turn the gas off before boiling, the moment it turns off, I ...
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4answers
71 views

When is it more efficient to blow air over a wet laundry in order to dry it - when it's wetter or when it's drier?

If I want to speed the drying of laundry and allocate for it one hour of fanning - should I use it just after I hang it to dry or several hours later? When we want to cool hot tea it's better to add ...
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1answer
45 views

Why does salt ions is not exist at vapor when the water is boiled and evaporated?

I would like to understand when the water is boiled only pure vapor is produced and ions do not exist with vapor. Why? Can't the ions stick to water vapor? And Are Na+ and Cl- have boiling points? ...
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5answers
72 views

In thermal spas the temperature of steam is about $50^{\circ}C$, but feels way hotter. Why?

So when you're in hot water and start to move or something the steam feels really hot even though I read its temperature is about 50 degrees Celsius in thermal spas. So why does it feel that warm?
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2answers
41 views

What happens when the saturation pressure of a substance is greater than its actual pressure

I am facing difficulties with understanding the relationship with saturation pressure and the phase change (from liquid to gas) of a pure substance. Let's suppose I have some amount of water at p = 5 ...
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2answers
44 views

Density of Sea Water [duplicate]

Understandably, there is a clear-cut difference between liquids and gasses. Gasses being more compressible, liquids less so. If you bring a volume of air sealed in a container from sea level to 10k ...
1
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1answer
45 views

What causes these diamonds in water droplets on a screen?

It was raining yesterday and the screen of my iPad ended up covered in varying sized water droplets. As you can see, the smallest water droplets look transparent, and then as the size increases the ...
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1answer
28 views

Deriving relationship about water not falling down from a hole under a fast flowing stream [closed]

A gutter is tilted from an angle of $\theta$ with respect to earth. There is a hole on the gutter from a distance of $l$ (m) from the top of a gutter. What is the speed of the water that should flow ...
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3answers
84 views

Could a microwave oven be tuned to defrost well? [closed]

Typical microwave ovens do a lousy job of defrosting because liquid water absorbs their radiation far better than ice. So once a spot melts, it will quickly rise to cooking temperature while the rest ...
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3answers
149 views

What is the speed of a photon in water?

What is the speed of light in water? The speed of light in vacuum, divided by the index of refraction for water. And what is the speed of a photon in water?
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3answers
3k views

Why do water drops form spheres in space? [duplicate]

When water is poured out in space, why does it always take a spherical ball-like shape?
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1answer
59 views

How did Mars lose all its surface water?

A lot of geological evidence suggests that Mars once had quite a bit of surface water. I assume it wasn't whisked away into space, so where did it all go? What processes caused the water to go there? ...
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2answers
58 views

Can a diamond pipe prevent water from freezing and bursting the pipe?

I know a diamond vacuum blimp is not possible because it will implode under air pressure. Is it possible for a diamond pipe to keep from bursting with frozen water? I found nothing online except ...
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1answer
183 views

Why does ice freeze in feathery streaks on windows?

A twitter acquaintance asks: ...why does the ice form in feathery streaks like this?
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1answer
59 views

Water at 0 atmospheric pressure

Suppose I put a bucket of water on the surface of the Earth. Then somehow the atmosphere disappears. My question is: Would the water fly out of the bucket, or would it be still there? My reasoning ...
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1answer
28 views

How can I find inlet pressure of a valve by measuring the mass flow rate? [closed]

I don't have a manometer to measure how much pressure of water my inlet valve is having, can I measure this by just having an empty container and have the valve fill it per x amount of seconds x ...
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4answers
194 views

Why are water waves transverse or up and down? [duplicate]

why are water waves transverse? why aren't the Longitudinal?
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4answers
71 views

Can someone explain why there is water in this vacuum chamber?

I work at a water treatment plant that uses a vacuum system to pull the water into the filters and backwash the filters. In the middle of the vacuum system there is the vacuum chamber. What I don't ...
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0answers
45 views

Why perspiration drops are seen in shopping bag?

Why perspiration drops are seen in shopping bag? When i put hot bread in shopping bag after sometime i saw perspiration drops in the shopping bag.
2
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1answer
75 views

Boiling water in metal pot

This is something I've observed when boiling water for tea. I place the water in a metal pot and bring it almost to a boil. The water level is at about the middle of the height of the pot. When the ...
2
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0answers
52 views

Forces acting upon body on impact with water

I am investigating the water-entry of a steel ball-bearing at different speeds. Ideally, I would like to model (to an extent) the forces experienced by the ball bearing as it transitions from air to ...
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0answers
26 views

What is the most energy efficient way to heat and maintain the temperature in a tank (vertical column) of water with 4 heating elements? [closed]

1) Given the following tank of water with four heating elements in two groups, A and B, where the elements in each group are switched on and off together, what is the optimal way to heat the tank of ...
1
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1answer
35 views

Why does using deuterium mass for hydrogen improve convergence of molecular dynamics simulations of water?

I've come across many papers performing ab initio MD (Carr-Parinello or Born-Oppenheimmer) simulations of water that use the deuterium mass for hydrogen. And they state that this helps improve ...
1
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1answer
36 views

Water climbing up sandpile against gravity?

I have seen a bucket full of water, and sand in it so that the sand just creates a pile just above the water level, and the sand that is above the water level is first dry. As time passes, the water ...
12
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4answers
2k views

Could you have sand pipes like water pipes? [closed]

It's common knowledge that sand behaves like water when in small grains. So can you make a pipe that carries sand in the same way pipes carry water? If not, is there another way you could?