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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158 views

Can a hose filled with water go up if there is not a lot of pressure?

This might be more a general knowledge-type question or physics basics (or maybe not even physics) if so, I apologize and never took a physics class (my school never offered it), so I am not really ...
0
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1answer
259 views

What wavelength of light is the least absorbed by water?

As I understand it, an infrared laser range finder will not work underwater because the infrared rays are heavily absorbed by water. What wavelength (optical, ultraviolet, microwave, etc.) of light ...
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1answer
53 views

Difference of water pressure

We know that $P = \rho gh$, so is it true that water pressure at 2nd floor will be higher than water pressure at 9th floor of a 12 story building?
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0answers
34 views

How fast does water have to be moving for it to gain a lot of heat? [duplicate]

A random question popped into my head a few minutes ago: objects, when moving fast enough, start to get resistance from the air. Since there is friction between the air and the object [water], there ...
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3answers
203 views

Why is alcohol less dense than water?

Ethyl alcohol (ethanol) is less dense than water, and it's boiling point is lower. But this molecule is more complex and bigger than the simple H2O. How can a substance with a higher molecular size ...
25
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2answers
3k views

When a drop of water falls into water, where do the splashes come from?

When a drop of water falls into a reservoir of water from a high enough altitude, water droplets will splash (image credit): My question: Does the water in those droplets come from the original ...
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1answer
79 views

Are particles that locally evaporate off water's surface at T = 100?

Water molecules can evaporate off a surface without needing to boil (How does water evaporate if it doesn't boil?). This is because surface particles are sometimes energetic enough to overcome ...
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0answers
46 views

What is the spheroidal temperature of water?

I understand that when a hot plate reaches a certain temperature water will no longer wet the surface, but will form perfect spheres on the surface of the plate. The temperature at which this happens ...
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2answers
139 views

Why water boiling time depends linearly on water volume?

I thought that the function will follow the Square-cube Law since we heat water at the surface (which is x^2) while we heat the volume (which is x^3) as it happens in animals according to Bergmann's ...
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0answers
34 views

Superheating Water Demonstration with a Vacuum

There are many Youtube videos which place a cup of water into a vacuum chamber and cause boiling around 0.020 atm, but I can't find any which show a vacuum-only "superheating" effect (to be clear, I ...
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1answer
730 views

Why does sound not travel between media?

So imagine you're at the beach; you go into the water and the moment you enter the water you stop hearing anything from the outside world. The same happens vice-versa: your friend shouts at you from ...
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1answer
95 views

What makes bathroom soap bars to crack during winter season?

Is there some relation between winter season and cracking of bathroom soaps? I noticed that , cracking happens only during winter season.I also learned earlier from physics stack that, During winter ...
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2answers
75 views

Why is water such a poor electromagnetic conductor? [closed]

1.-Why does salt water not conduct any form of non-visible light? 2.-Why does it conduct red light so much worse than other colours? (Why does it absorb red so much and not blue, for example). It's ...
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4answers
653 views

Better explanation of why an object floats: density? or buoyancy in equilibrium with object's weight?

Across StackExchange, you see two explanations for why an object floats: The buoyant force, equal to weight of displaced water, is in equilibrium with the object's weight. The density of the object ...
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2answers
467 views

How long will it take to fill a bath tub with oil compared to water?

As everyone knows, the oil is more viscous than water. But, I've been wondering how long it will take to fill a bath tub compared to water. It is quite obvious that oil will take longer. But, how much ...
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3answers
4k views

Why is ice less dense than water?

The answers to this question explain that ice is less dense than water because it has a "crystal structure", but they dont explain what exactly that is and why this happens, also I saw this answer ...
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3answers
3k views

Air Regeneration in Closed Systems [closed]

I wonder what's the way to regenerate O2 in air without using consumable chemicals (where one can use electricity through electrolisis or using UV lamps)? We can dissolve water into O2 & H2, but ...
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3answers
26k views

Why does water pouring from a glass sometimes travel down the side of the glass?

If you have a glass of water, say, three quarters full and you pour it at an angle of say, $45^{\circ}$ with respect to the the table, the water comes out of the glass and goes directly down towards ...
2
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2answers
151 views

How does a rising bubble take a dome-like shape?

Since I have swam on the swim team for most of my life, I am very familiar with bubbles. I know a raindrop falling through the sky gets its shape because it is the most aerodynamic shape, but how come ...
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1answer
41 views

Hydrostatic pressure in a vase at different depths

I am building a water level sensing device on the base of Arduino. The sensor is the eTape by Milontech. The resistance changes almost linearly with depth as the sensor is immersed in liquid (...
9
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1answer
1k views

What determines bubble locations in boiling water?

Something a little different to our usual fare. I was boiling a pan of water for cookery the other day, and got to wondering what caused the location of the bubble streams from the bottom of the pan. ...
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0answers
12 views

Capillary bridge force function given volume and distance

Given two surfaces and a fluidic glue with sufficient adhesion, what is the force provided by the capillary bridge provided the cohesive properties of the glue, volume, and distance between the ...
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1answer
357 views

If I mix 1 unit of water at at 30C° with 1 unit of water at 60C°, is the resulting water at 45C°? [closed]

I'm curious how temperatures work when mixing water. I'm not very good at physics but I'm always learning. Let's say I've 1 gallon of water at 30C° and 1 gallon of water at 60C°, and I mix them ...
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4answers
3k views

Force of an impact on water

Today, at the Brazilian news, I heard that a men fell from a cruise into the sea, from a height of 50m, and decided to see if he could have survived. I took his weight for being 80kg. I did $V^2=V0^...
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0answers
58 views

Entropy changes of water

I have a few questions regarding entropy and water. Suppose you cool down water so that it freezes at $273.15K$. How is entropy positive in this case? I have a feeling it may have to do with the ...
23
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1answer
1k views

Why does a water drop on a hot plate at 150°C evaporate faster than on a plate at 200°C?

I recently read that: A drop of water landing on a hot plate at 150°C (300°F) evaporates in a few seconds. A drop of water landing on a hot plate at 200°C (400°F) survives a whole minute. How ...
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2answers
1k views

How much better is salt water at letting through microwaves than pure water?

Radio Wave Attenuation There are two general types of matter (substances) in the universe that affect electromagnetic waves, conductors and insulators which are called dielectrics by ...
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1answer
585 views

Distinctive properties of liquids

The molecules are closely arranged in solids, loosely arranged in liquids and are free to move in gases... But, Why are liquids (especially water) exhibiting these distinctive properties such as ...
0
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1answer
32 views

Can there be net condensation into a pool of water?

I'm curious about the equilibrium of evaporation and condensation. Given that the surface area of a dehumidifier's evaporation coil at 4C is proportional to the rate of condensation, how would the ...
0
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1answer
93 views

Time to decrease water temperature by 5F from different initial temperatures

Is the time to (naturally) decrease temperature of water by 5 degrees the same, regardless of the initial temperature? Imagine 3 glasses of water (a, b c) in a room temperature of 70F. There are 3 ...
4
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3answers
2k views

Why does water reflect light?

Why does water reflect light? What is actually happening when light is reflected by water? We know why metals reflect light; water, however, is not metal, but it still reflects light and we can see ...
0
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1answer
637 views

Water evaporation

It is known that molecules at the surface are more strongly attached to each other (more attraction less repulsion) than those within the bulk (attraction and repulsion are balanced). This is the ...
40
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8answers
49k views

Why does ice melting not change the water level in a container?

I have read the explanation for this in several textbooks, but I am struggling to understand it via Archimedes' principle. If someone can clarify with a diagram or something so I can understand or a ...
0
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1answer
115 views

How does pressure increase underwater?

How it is that when we go deeper in water(seas or oceans) the pressure increases, while water(generally liquids) are incompressible?
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3answers
131 views

Is there an way water can burn or cause fire?

Water known as the fire extinguisher.What is the possibility watere being the fuel to fire. "Pure water"
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3answers
14k views

Why does the water level equalize in a series of tubes?

Say I have a series of tubes (not the internet) looking like this, where w represents water: ...
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1answer
30 views

Water's Specific Heat Capacity as an Outlier

Can the specific heat capacity of water being ridiculously high as compared to other substances be explained at a molecular scale?
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0answers
112 views

Finding an equation for the cooling curve of water with respect to surrounding temperature

I would like to find a general equation that describes the cooling curve of water from 100 degrees Celsius to the surrounding temperature $T_s$ against time (say, in seconds). As far as I know and ...
2
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3answers
456 views

Does water absorb neutrons?

Water is used as a shielding material in nuclear reactors. What's its function as a shield? Does it absorb neutrons and is there a reaction between water and neutrons?
0
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1answer
63 views

Viscosity of Muddy Water

How do I calculate the viscosity of muddy water at 25 deg C and knowing the weight of undissolved solids either SiO2 or Al2SiO5 in H2O, grain size < 150 microns? Do I have enough information to get ...
0
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0answers
35 views

What are the physics principles behind “amphibious” camera lens windows?

Underwater camera housings have a window through which the lens looks. When the camera surfaces, a couple of things can happen, and I've seen both captured in the camera footage. In one case, water ...
4
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4answers
257 views

why water molecules in vapor contributes to the green house effect and water condensed in drops not?

I am a teacher planning a unit on climate change. I came across this statement: "Clouds are water vapor (green house gas) and water molecules will reflect heat into space… actually clouds are ...
5
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2answers
2k views

Why do some things crystallize? (And others don't, for that matter.)

Ice, for example, will form a crystal when frozen under certain circumstances. Why is this the case for ice? While on the subject of water crystallization, why do snowflakes usually form in base 6 ...
6
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3answers
2k views

Why is steam used to spin turbines?

The ideal gas law tells us that the relationship between Pressure (P), Volume (V), Temprature (T), and quantity/amount (n) is $$ PV = nRT $$ where R is the gas constant. Say your an engineer who ...
2
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1answer
94 views

Why is modelling water so difficult?

There are several models of water that have come into existence so far. Nevertheless, there is no one particular model which effectively gives all the properties of water correctly. A model like TIP3P ...
4
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2answers
104 views

Why does soaking something soften it up [duplicate]

Apologies if this is duplicate, I've dug around and can't find it. If you leave a sponge/cloth out to dry for a while it eventually becomes slightly stiff. Upon wetting again, however, it softens up ...
4
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2answers
6k views

Why are refrigerators 4 degrees and freezers -18 degrees?

I assume that the refrigerator's temperature of 4 degrees has something to do with the fact that water is densest at that temperature. Does that inhibit microbe growth? But what about the freezer, ...
0
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1answer
483 views

Why do hot tubs dehydrate you? [closed]

I was just sitting in a hot tub for a few hours with friends, and we all noticed we really wanted to drink some water. We felt dehydrated. I tried looking up why hot tubs dehydrate you and all I got ...
0
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2answers
442 views

Does water follow the path of least resistance

I am having hard time proving this either right or wrong. Let's take for example a river, does the water flowing down follow the least resistant path?
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8answers
24k views

Why does hot oil explode when pouring water on it?

What is the reason that hot oil makes sound and explodes when water is poured on it?