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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30 views

Water molecule Resonant Frequency

If water is subjected to microwave energy at the water's exact resonant frequency but 90 degrees out of phase, would the water molecule cease vibrating? Would the water then freeze or be cooled at ...
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2answers
64 views

Why Counter waves are being produced in water?

While studying water waves in a cuboidal tank, the following observation was made. A gentle tap on one side (A)of the tank, generated waves from that side towards the opposite (B). At the same ...
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1answer
237 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 ...
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2answers
237 views

Does water diffuse trough rubber of car tire of when liquid or only as gas [closed]

Does Water difuse trough rubber of car tire when its liquid or only when its a gas. Can also be that is diffuses but slower when liqiud. I want to know this for my argumentation that filling car tire ...
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1answer
30 views

Pumping water vapor into liquid water [closed]

Do liquid water and water vapor count as different types of matter? How does Second law of Thermodynamics apply when I pump water vapor into liquid water? What would happen when water vapor goes into ...
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0answers
28 views

What makes some air bubbles in water more persistent?

In a plastic bottle of water, near the walls, it is common to observe the presence of little bubbles (I would estimate them to be $\approx0.5$mm in diameter. In my experience, most of these bubble ...
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1answer
30 views

Why is water expelled more powerfully from a trigger hose the moment its triggered?

I think its something to do with acceleration but can't put my finger on it. Something about the most power needed as the greatest acceleration, as water flows up to full rate the accel and thus ...
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1answer
105 views

Using water pressure as pushing force in a floating bath tub? [closed]

Does physics allow for water pressure to work in this way? if so What formula can prove this? (backup link 1, backup link 2)
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1answer
40 views

Best frequency for Underwater Transmission

What is the best frequency of transmission of under the water for communication with good data rate? I have read that the threshold of hearing underwater is around 170 to 180 db. Can this be useful in ...
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0answers
26 views

How does air going through silica gel change its humidity

Assume that the properties(temperature,humidity,velocity and so on) of the incoming air flow stay constant. The air flow goes through a silica gel plate. Humidity of the air will decrease, but how to ...
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2answers
2k views

Compression and expansion of solids vs fluids

Why is it that solids on compression [As in striking a hammer etc.] heat up, but liquids and gases on compression [Pressurizing liquids causes them to freeze or gases to liquify] cool down? Can ...
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5answers
65k views

Freezing point of water with respect to pressure.

I know when the pressure is reduced, the boiling point of water is reduced as well. But how does the pressure affect the freezing point of water ? In a low pressure environment is the freezing point ...
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2answers
996 views
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7answers
8k views

Why does ice form on bridges even if the temperature is above freezing?

So with this "arctic blast" continuing, I've noticed that for my area, the temperature drops below freezing just long enough to cause freezing rain, but then the sun comes out and the temperature ...
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3answers
114 views

Shaking water inside bowl causes waves but why does the water stabilize?

Suppose you shake water inside a container, then at first the waves goes up and down strongly but they gradually dissipate. What makes them dissipate?
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1answer
21k views
3
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0answers
37 views

Detect ions in water using impedance spectroscopy

I would like to check the presence of Na, Ca or other ions dissolved in water using impedance spectroscopy. I was thinking that because the ions have different masses they will have different ...
0
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0answers
17 views

How much power is being actually delivered by an electric heater to a cooking pan?

I've been doing experiments on an electric heater heating a cooking pan filled with 2 litres of water, from 20°C to 70°C; now I'm trying to draw a theoretical heat transfer model thath should match ...
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1answer
44 views

How does water height in a vacuum chamber effect pressure

I am testing for package leaks in non-porous packages. Quick details are: 1) Package is sealed at atmospheric pressure. There is some headspace inside the package which is just air. 2) A small hole is ...
0
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1answer
26 views

Why do water droplets not form on large openings such as pipes?

When you have an object with a small opening, such as a pipette, water droplets form and hang easily. However, when you have a larger opening such as a pipe, the same water droplets do not form. Is ...
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1answer
101 views

Why does microwaved water kill plants? [closed]

I've read tons of articles about microwaved water klling plants and the most of them said it was a myth. So I decided to do this experiment myself on cress plants. I repeated the experiment three ...
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0answers
32 views

Is an “underwater” submarine affected by a nuclear bomb exploding above the water? [duplicate]

I've just read Would being underwater help survive a nuclear bomb?. Submarines are way more armored and far from the surface than a human body (https://en.wikipedia.org/wiki/Submarine_depth_ratings), ...
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1answer
70 views

Is water boiling an excited state?

I was wondering and arguing (pro) with a friend that the process of water boiling is an excitation. I based my opinion on the theory that excitation is an increase in the energy level of an atom. I ...
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1answer
36 views

Why doesn't the fridge condense water like an air conditioner? [closed]

Simple question, why doesn't the fridge condense water like an air conditioner? I know that my ac condenses water (even in cool or heat) and don't know why the fridge doesn't. Aren't they both ...
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2answers
36 views

How many water wheel can fit on a river until another one produces zero energy?

Mostly what I'm after are the factors I need to know to do the problem. Imagine we're in the days of Leonardo Da Vinci. And pizza is everyone's favorite food. And there's a river that goes on ...
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1answer
26 views

Force on sides of a pool [closed]

I am going to create a large pool of water for a stage production. The volume of water will be 6m x 5.2m x .15m deep. I want to check how much pressure or force will be exerted on the surrounding ...
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0answers
38 views

Solving propulsion force of water rocket

As a note, I am not a physics student, although I am familiar with many physics concepts and calculations. I am trying to calculate the force of the thrust of a water rocket. I started with the ...
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1answer
17 views

Simulating open water acoustics in a tube

For the purpose of testing an underwater acoustic transmission it is possible to use a tube filled with water with a transducer at one end and a hydrophone at the other. The problem is that sound will ...
0
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1answer
13 views

By which factors are tides and waves affected?

To my understanding, the tides and waves on Earth's oceans are caused by various factors such as the moon's gravity, the water cycle (rains, storms, evaporation), Earth's rotation, etc. Although the ...
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2answers
12k views

Why is boiling water loud, then quiet?

Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was ...
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1answer
34 views

How do buoyancy control devices (BCD) work?

I get that having more air decreases density and increases buoyancy. However, we can take the diver-BCD-oxygen-tank to be a single system. How can the pumping of air from the tank into a vest around ...
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2answers
96 views

volume of the air bubble in the water

How does the depth affect the volume (the radius) of an air bubble in the water, if the temperature and density of the water are constant. Is there any relation combining this? Can I say that ...
4
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2answers
130 views

Water bombing - risks and possibilities

I just saw a video on youtube, where an excavator drops a load of water on a car, destroying it completely. I also saw a video with a fire-fighting plane dropping even more water on a burning truck. I ...
3
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1answer
38 views

How quickly does the temperature rise in a water container submerged in a hot water bath?

Let's assume I have a small bottle (neglecting any insulation from the walls of the bottle) containing e.g. 150ml water at 4°C and place it in a larger pot with sufficient water at 80°C so that the ...
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4answers
108 views

The impatient hot tub owner [closed]

An impatient man owns a 300 gallon hot tub. He comes home from a hard day of work and sees that his hot tub is currently simmering at 90F. For maximum relaxation, he wants it at 104F. However, the hot ...
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2answers
86 views

Does shaking a kettle whilst boiling increase the temperature faster than a statically-placed jug?

Water molecules move faster at higher temperatures. Does shaking a boiling kettle whilst it is in the process of boiling water increase the rate of rising temperature ? Is it worthwhile to do so ...
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2answers
541 views

Will an object with a higher temperature lose its heat faster than a cooler, yet warm object

I'm after the math, which I don't understand yet and can't find elsewhere. The variables are: Two identical cups, A and B The same volume of fluid is contained in each cup, test fluid is water. ...
7
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3answers
726 views

Why is salt so hard to remove from water?

Water molecules and various salt molecules are very different. However, it seems very difficult to separate the two. Once a salt is dissolved in water, an energy or chemical intensive method (like ...
5
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1answer
3k views

Do my noodles cook quicker when the water is boiling or when it is just about to boil?

I was just cooking some noodles and staring at the pot waiting for them to cook made me wonder... Will my food cook quicker when the water is boiling and bubbling, or when it is at a temperature where ...
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0answers
15 views

Is there a relationship between maximum flow rate of a fluid through perforations in a cavity and the flow rate of the fluid in the cavity itself?

I have a scenario where water is flowing horizontally through a (rectangular) cavity. The underside of the cavity has a set of perforations that look something like: and I need to determine the ...
4
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2answers
642 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 ...
3
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3answers
314 views

Effect of initial suction power on siphon performance

Background I have a flooded crawl space and I'm using a long hose to siphon the water out. I do this as follows: One side of the hose is in the crawl space, and the other side down a hill in the ...
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0answers
45 views

Can 1km diameter ball of water preserve it's integrity before hitting the ground falling from 10km altitude?

I still argue with my friend over some big ball of water (1km in diameter) that is being instantly created 10km over the surface of the earth in perfect sphere form. I stated, that as it hit the Earth ...
3
votes
1answer
68 views

A model for constant temperature of water in a container

I put some water in a container with initial temperature $T_0$ in a room, and the room's initial temperature is $T_a$. Now the container is filled to the maximum, so any more water coming in will ...
1
vote
1answer
53 views

How does water at different temperatures behave when they are mixed? [closed]

If I were to inject a constant flow of water at T1 into a reservoir of water at T2, how does that effect the temperature of the mixture at different points in the reservoir? In other words, what ...
2
votes
2answers
189 views

Are raindrops actually “shaped like tears” when they fall?

Raindrops are always pictured like this, people imagine they have this shape when they fall, but is this true? Doesn't this shape create too much drag? What shape do they really have? It would also be ...
2
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0answers
29 views

Does a rapid temperature change crack annealed glass [closed]

Over at Lifehacks.SE there is a question about how to remove ice from a windshield. One answer suggests using water but warns that using boiling water might crack the windshield. As far as I ...
0
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1answer
55 views

Stiffness in water

How do I find the stiffness or Fluid Elasticity for water (at a given temperature of for example 40 degrees)?
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1answer
895 views

A water balloon in vacuum: does it boil?

If I put water in a vacuum it will boil. But what if I put this water inside a balloon ? I searched for answers and fount this video: http://www.youtube.com/watch?v=9q8F3ClUuV0 It seams that the ...
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0answers
13 views

Fermi estimate for ice nucleation timescale

My friends in a Cryo-EM lab freeze their very samples quickly, a process they call vitrification. The timescale for this process is milliseconds (from wikipedia): The production of amorphous ice ...