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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3answers
258 views

Why can't we stand on fluid surface if newton's third law is applicable [duplicate]

I try to stand on water surface but I just drown. A book resting on the table because of the W(gravitational Force) and normal force of the table acting on the book oppositely in equal magnitude ...
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Can water boil at 100% absolute humidity?

The definition of absolute humidity is the amount of water that can exist in solution with air as a gas. My question is, in a closed vessel that contains a flask and a burner or heat source below it ...
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118 views

Is it easier to lift an object in air rather than in vacuum?

I was reading about why lifting an object in water is easier then in air. The explanation goes on the line that the water which was above the object will fall downward and sideways, taking the place ...
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1answer
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Could H2O have a 4th phase rather than 3? [closed]

I just finished a book which is hard to argue: "The Fourth Phase of Water" by Dr. Gerald H Pollack. He states there's a negative layer of H2O (which is termed the 'Exclusion Zone') which develops all ...
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1answer
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Why does a near UV laser show as a green path in tap water?

i am using a 405nm laser and shining through a glass with regular tap water, also i noticed that it shows as an almost white path in the thick glass bottom, what causes this?
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How would a fixed triple point of water cell respond if the pressure was raised with additional (liquid) water?

May be a basic question, but I'm a technician, not a physicist (or physics student.) I came across triple point cells in some research on practical thermometer calibration, and I'm having a hard time ...
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Wood vs static Water

First of all: I'am not a physicist or anything close to it. I jhust enjoy to think about certain thinks in a different way and to ask for a much more detailed "how". So here is what keeps me from ...
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Force of Body Impact Upon Water

So in 2014 I fell from 70 feet and landed flat on my back on slowly moving water (.5ft/sec) on the Willamette River. I weighed aproximately 190 pounds at the time. I was curious if someone would help ...
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117 views

Calculating the rate of pressure increase in a water-filled boiler

I'm trying to think about how fast the rate of pressure will increase in an idealized boiler filled with water starting at 100°C, standard pressure, and supplied with 1000W of power. I'm assuming a ...
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2answers
359 views

Why does water splash up?

I’ve noticed occasionally whenever I start to put down a glass of water quickly it splashed up, even without it making contact with the desk. And another example is when I have the faucet running ...
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2answers
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What happens when you put water under intense pressure?

Pretend you have an indestructible tube that cannot leak, inside which is water. Imagine that in each side of the tube, you have very powerful pistons What would happen if you compress the water ...
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1answer
448 views

Final temperature of ice and water [closed]

My answer doesn't seem likely but I can't see where I've gone wrong: Q: Ice of mass 0.125kg at -5 degrees is added to water of mass 0.25kg at 8 degrees. Calculate the final temperature of the water ...
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1answer
278 views

Condensation of water

So I was wondering why does condensation occur at the molecular level. I can understand evaporation as the external atmospheric pressure being less than the vapor pressure ( energy of the water ...
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923 views

Refraction: Swimming goggles, short-sightedness, and underwater vision

I have thought of this question due to personal experience. I am short-sighted, and over the last three years my short-sightedness has worsened. Taking a lifeguard certificate again now that I did ...
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2answers
97 views

Can I suck water out of a full bottle?

If i have a bottle full of water (there's no air in the bottle) with a straw in it and the bottle is sealed completely without any opening except the straw, will i be able to suck water out of the the ...
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Is water really $H_2O$? On a comment concerning the quantum mechanical description of water made by Hilary Putnam [closed]

I wanted to pose a question here (also posted to r/physics a bit earlier) and was hoping the you all might be able to help. I was re-reading a book by the philosopher Hilary Putnam titled Naturalism, ...
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1answer
445 views

Water pressure depth vacuum?

Recently I saw an article describing Static Fluid Pressure which says "The pressure exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration ...
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1answer
110 views

Airplane trails

Some airplanes leave a trail through some regions of sky. This post explains why it is so, but it seems not enough. The trail is said to be made mostly of water which, on a specific altitude, ...
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1answer
71 views

Do sound waves in the ocean reflect off the surface at 90 deg incidence?

Let's say you have a sound source, in the ocean, at a frequency around 50 kHz. It's a point source, so the sound waves emanate in all directions. Some will go straight up. Do these straight up sound ...
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1answer
2k views

Do water waves moving from deep water to shallow water always have higher amplitude?

I've seen many images like the following one that the height (amplitude) increases as the water becomes shallower. However, I also found some images showing that the amplitude remains unchanged. So ...
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1answer
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Strange ice found in my garden

This morning I found a really strange ice formation in my garden. I can't figure out how it appeared, because there was nothing above. The night was particularly cold (Belgium). To give an idea, it ...
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1answer
672 views

Ice floating on water [duplicate]

Why is the hydrogen bond different from other bonds that allows ice to float in water rather tan sink. I don't want the math. I want the reason that bond is different than the rest. Why, not how.
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1answer
100 views

Whose electric energy consumption 'copper' or 'aluminium' element in Water heater will be greater?

Considering water of 20 litres 25 degree celsius of temperature needs to be raised. Using the heat equation q=mcpdt considering cp of water to be 4.2 kJ/kgk we get q=2100 kJ which equals 2100000 J. It ...
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2answers
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Theoretical vs Experimental flow rate of fluid coming out of a water bottle with a hole in it

Say there is a water bottle that is filled with 300 mL of water and has a circular hole with a radius of 2 mm. In this bottle, the water sits 7.8cm above the top of the hole (which has been drilled 1....
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2answers
2k views

What is the difference between vapour and steam?

What is the difference between vapour and steam? These two terms seemingly are similar but have different meanings. trying to define these two gets us a similar definition which is not actually true I ...
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Why can I touch hot things longer with water on hands?

So I have done a couple of personal experiments with water on my hands. One day I was taking bread (rolls to be exact) out of the oven with my bare hands and burned my hands when my hands were dry. ...
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2answers
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Does air have to be oversaturated in order to make resublimation possible?

I am writing a pre-scientific work about the chemtrail conspiracy theory. A part of that is the exact process of contrail formation. There is one more puzzle piece missing. Hopefully the answer to ...
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1answer
94 views

Determining friction force while stirring water

So I researched a bit on this, and found a video which showed an experiment in which he boiled the water, just by pouring it into a high-speed blender and stirring it. Can someone tell me how can I ...
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0answers
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Water vapour behaviour during hypersonic expansion

I have a question about the behaviour of air with a small mass fraction of water vapour at extremely low pressures and temperatures. I am currently running experiments in a large vacuum facility that ...
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2answers
147 views

How realistic is it to dry clothes in freezing weather?

There are stories about clothes freezing and drying in cold weather. The typical reason given for that is that the water is undergoing sublimation (ice -> vapor). The phase diagram for water is In ...
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1answer
58 views

Dependency of $\mathrm{H_2O}$ surface tension on vapour pressure

How is does the surface tension between: liquid water, and humid air depend on $\mathrm{H_2O}$ partial pressure in the air, and temperature? Edit: I assume that temperature and humidity will both ...
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1answer
79 views

Can particles be sucked into a pipe while water is pushed through it

The picture below shows a piece of equipment dentists use, called a "water scaler". As you can see, there's water spraying out of it through a very small hole right in front of the bend. I've been ...
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1answer
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How does surface tension allow the surface of a liquid to exert an upward force on an object?

I've seen partial answers to my question on Wikipedia and several other questions on this site, but I'm not quite grasping how intermolecular forces lead to the creation of a membranous boundary ...
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1answer
37 views

How to evaluate how fast water in a bottle is heating when moved rapidly?

Let's assume I have a bottle of cold (> 0°C, but close) water and the environment has about 25°C. I am eager to drink this water and I am moving the bottle to reach at least 15°C. I am thinking ...
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1answer
93 views

Does water get displaced by itself when being filled in a glass or does it “pile up” like a denser substance?

Disclaimer: I do not have a very strong background in physics so if this is too elementary I apologize The Question: When water is being poured into a glass, is the stationary water (i.e. that which ...
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When can water be supercooled?

Qualitatively, I understand that water can be supercooled when: It is relatively pure. It is in a container that is relatively smooth of defects. The effect of both of these is to reduce nucleation ...
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6answers
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Why does water stop boiling immediately after turning off the heat?

When I am heating water on a gas stove, it begins to boil after some time and bubbles of air can be seen escaping out. However, as soon as I increase the amount of heat in the stove, the rate of ...
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1answer
27 views

Van Der waals forces

Dipoles occur in the formation Van Der waals forces. Van Der waals forces are said to cause clusters of water molecules to form even in liquid water. If this is correct then why don't we see increase ...
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2answers
558 views

Water with low surface tension

I am working on a project to Emulsify Water and Diesel, is there a way to reduce the surface Tension of the water to Zero or close to, so that the two will mix, without the use of Chemicals or ...
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7answers
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Is it possible to prevent water from cooling by keeping it in an rigid container?

If you fill a soft plastic water bottle with hot water, close the lid, then cool the water down, the bottle will contract. When you open it up, it will expand again. Conversely, if you used a hard ...
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1answer
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How do I calculate how long water will take to warm from 22°C to 35°C?

I'm a microbiologist and my physics is not up to par for figuring this out. I've requested our engineering department to perform a temperature mapping of the vessel, but they can't do it for me. I ...
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1answer
292 views

mysterious waves while boiling water

When you take a container with water and begin to heat it, after a while, you will notice that bubbles begin to form. If you wait a bit longer, you will easily (it's so clear) start noticing smudgy ...
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2answers
125 views

Hot Tub heating connundrum

I registered to ask this specific question because it completely does my head in. I am not so much asking this question because I don't understand the answer, but because I find it massively ...
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3answers
343 views

Prevent water tank stratification through thermal conductors

I have heated water in a tank that is undisturbed (no inlet/outlet, no stirring). Due to the cooling of the sides of the tank, it will over time naturally stratify into a top temperature layer and a ...
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2answers
75 views

Air temperature that would cause same rate of heating to human body as a 40°C hot tub

My son was wondering why a 104°F (40°C) hot tub feels so much hotter than a 104° day. I explained the difference between conduction and convection but we started wondering how hot the air would have ...
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2answers
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What is the equation relating the mass of water and its temperature change in a fixed time?

I heated up a beaker of water to 70˚C and set a time of 2 minutes. I measured the change in temperature in that time interval. I changed the mass of water and measured the change in temperature each ...
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How does the lowered surface tension of soapy water make it better for cleaning?

I've read a few other answers on similar questions that talk about the lower contact angle and lower surface tension with soapy water (compared to tap water), but nobody seems to mention how this ...
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4answers
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can water pressure differentials provide power

If you pumped water into the top of a water tower and vents were added to the top of the water tower to separate the tower reservoir from the pump to make two different but related systems. The tower ...
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3answers
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What is the reason for this pattern of noise in electric kettles?

It always seemed to me that the noise from electric kettles follows a pattern: It starts low, then increases, and decreases again before the water starts to boil. To verify this, I performed a little ...
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2answers
523 views

How far can I spray water in a straight line from a pump knowing the pressure and flow rate?

I want to build a water gun (think super soaker) powered by a water pump. If I know the flow rate and pressure of a pump, can I calculate how far a jet of water will go in a straight line, assuming ...