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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Average Rate of Evaporation of Water

Consider a container of volume $V$ and cross sectional area (exposed to another fluid, say air) $SA$. The container is at constant temperature $T$, and contains $N$ molecules of water, where $N$ is ...
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1answer
44 views

effect of opening the barrier between a tube with one side pressurized and the other side a vacuum

What would happen when a tube with an air space pressurized to 500 atm by the water exerted at 5 km below the surface was opened into a vacuum chamber rising up 5 km to the surface? The bottom of the ...
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1answer
47 views

Surface tension in a balloon wtih water [duplicate]

Imagine such situation: We have an empty balloon. We put a long, narrow tube into this balloon and we fill it with water. Then, the volume (and surface) of the balloon will start to increase. The ...
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2answers
45 views

Can vaporization heat added to the whole volume of liquid before vaporizing it?

It seems, for example a volume of water is heated to boiling point, then part of the water is vaporized, while the remainder need much more heat to vapor, which means that part doesn't receive latent ...
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0answers
12 views

Why Flow meters are some times showing -ve fluctuating Values in Pressurized Pipe lines [closed]

In our Underground Water reservior we are pumping water by Hydro-pneumatic pumps to maintain same pressure till last connection. in order to measure the flow we have installed precise electromagnetic ...
18
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3answers
2k views

Why does water feel cooler than air?

My first assumption was based on "evaporation causes cooling" but I realized that it is not the case as it is cooler even if I am submerged under it. Are all liquids generally cooler than air ? Just ...
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3answers
51 views

H2O Fuel of the Future [closed]

So I was busy trying to solve the world's problems the other day and a thought crossed my mind. I came across some data about cars that run on H2O and I was thinking that this seems like a great way ...
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1answer
35 views

Optics of stationary waves

could anybody tell me how it Works if it comes to stationary waves created on the surface of water jet and optics? there are some crests and troughs which work like lenses, but if you have water jet, ...
6
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1answer
210 views

Melting ice: reversible or irreversible?

I am looking into whether the melting of ice (or any substance for that matter) at constant pressure and temperature is reversible or irreversible. Different sources say different things, and it may ...
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1answer
93 views

Water vs. Air : Heat Absorption/Capacity

I am not a physicist by any means and not even a current student, but nonetheless I am looking for an answer. Here is what I have gotten so far from university websites and other various resources on ...
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1answer
55 views

Noncoalescing and bouncing droplets

if you set a dish filled with water onto a loudspeaker or other vibrator and make vibration, When it oscillates, it is possible to hold small droplets on its surface for a long time. I mean, when you ...
0
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1answer
36 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 ...
1
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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 instant,...
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0answers
39 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 ...
0
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1answer
43 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 ...
1
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1answer
31 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 ...
4
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0answers
35 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 ...
3
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0answers
46 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
19 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
59 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 ...
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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 ...
-4
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1answer
106 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 ...
0
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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
77 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
45 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
39 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 ...
1
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1answer
27 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
57 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
48 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 ...
0
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1answer
17 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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1answer
18 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 ...
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1answer
44 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 ...
0
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2answers
147 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 $dh/dt=...
3
votes
1answer
60 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
136 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
116 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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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 ...
0
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0answers
47 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
3answers
335 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 ...
3
votes
1answer
81 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
55 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
299 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
votes
0answers
36 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 ...
1
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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 ...
0
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1answer
78 views

Stiffness in water

How do I find the stiffness or Fluid Elasticity for water (at a given temperature of for example 40 degrees)?
3
votes
1answer
159 views

Why do liquids form less bubbles when poured at an angle?

For example, I noticed that when I pour a soda on the side of a glass instead of directly into the cup, it forms less bubbles. This is also evident with rootbeer floats. Is this an actual scientific ...
1
vote
0answers
30 views

Do (or can) hydrogen bonds between water molecules neutralize their own polarity? [closed]

Do (or can) hydrogen bonds between water molecules neutralize their own polarity as indicated here: Hydrogen bonding as the mechanism that neutralizes $\mathrm{H_2 O}$ polarity https://groups.google....
7
votes
2answers
203 views

Why does warm water sink?

It is well known that water at 4C is denser than water at 0C. This is the usual explanation for why a body of water freezes from the surface (also it's because ice is even less dense, but that's ...
0
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1answer
42 views

How can condensation be aided?

I was wondering if certain factors of water vapor condensation can be aided? For example, being able to increase the saturation of water vapor via a certain method, or another example would be having ...
1
vote
1answer
39 views

Why does liquid flow along the mug [duplicate]

I have been wondering why situation described in the picture below happens Why does the water/milk or any liquid poured from the mug/bottle flow along the surface of the vessel instead of leaving it ...