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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1answer
33 views

Which are the radii of curvature in the Laplace Pressure formula?

Laplace pressure is given by $$\Delta p=\gamma \left(\frac{1}{R}+\frac{1}{R'}\right)$$ where $R$ and $R'$ are the radii of the curvature of the surface. Using the following diagram There are at least ...
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What is the intuition behind a high Froude number causing instability in uniform flow?

Uniform flow in an inclined plane becomes unstable for high froude numbers. I can follow the spectral analysis, but I am curious why I would expect high froude numbers to cause instability. What is ...
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Different colors and their heat absorption capabilities

I did an experiment in which small canisters (image attached) containing water, were wrapped around with colour papers of different colours were kept under the Sun (image attached) . The different ...
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62 views

Properties of water at a temperature of 300°C and a pressure of 3000 kPa

I'm using a online calculator, and it says that the boiling point of water at a pressure of 3000 kPa is 233.7°C. So then I understand that the water in is a superheated state (and thus still a liquid)....
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Why do small patches of snow remain on the ground many days or weeks after all the other snow has melted?

I often notice small patches of snow that remain on the ground in seemingly random locations, many days or even weeks after all other snow in an area has melted, and even when temperatures have been ...
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What quantity of freezing water could generate 300,000 joules of mechanical energy from expansion - enough to boil an electric kettle? [closed]

When water freezes, it expands with considerable force - enough to break glass and burst through copper water pipes. If this material expansion was harnessed - e.g. liquid water placed in a container ...
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51 views

Why does falling water become less and less focused as it falls down?

So, I was observing my water purifier fill up my water bottle and I noticed that the beam of water coming through it became less and less focused as it falls down more. Now, I do understand the ...
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Is the velocity of a fluid in a vertical tube constant? [closed]

Here is how I concluded that: Let there be two points $A$ and $B$ in a tube, $B$ being a little higher up. Using the Bernoulli's equation: $$P_B+\frac{\rho v'^2}{2}+\rho gh=(\rho gh+P_B)+\frac{\rho v^...
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Understanding water flow in a fertilizer injection system

I recently set up a small EZ-Flo fertigation system. This is a tank full of fertilizer solution that you attach to a pipe that you are using for a sprinkler or irrigation. As water flows down the pipe,...
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How does the existence of a liquid-liquid transition in metastable supercooled water explain the anomalous properties of ordinary liquid water?

There has a recently been an experiment reporting a direct measurement of the long-speculated-about liquid-liquid transition (LLT) in high pressure supercooled water (link to article). What they have ...
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Why doesn't ice in a glacier feel as cold when I touch it as the ice I get from my freezer?

When I was in Iceland, I went to a tour in a glacier and I remember the ice that was there. It looked and felt like a huge amorphous block of glass: hard, smooth, not wet, and not that cold. Not as ...
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2 connected tubes filled with water, placing a stopper in one and raising the other, how can I determine pressure exerted onto the stopper?

If I have two 20ml test tubes connected at the base via a thinner flexible U-shape tube and I pour a set amount of water (40ml) into one test tube whilst both are at level height, the water ...
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1answer
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Will an evaporation water cooler work better if the water in the reservoir is cool?

I d like to find out if a evaporation water cooler works better or worse if you cool the water in the reservoir. Let's suppose that the water in the reservoir is at some 10°C, will the cooler deliver ...
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1answer
25 views

Photon absorbtion in water as a function of wave length

Say you emit photons with wavelength $\lambda$ measured in nano meters from a point source with power output $P$ measured in watts. Say you then place a photon receiver at distance $d$ from the point ...
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Does capillary action work in moving bodies?

If I were to have a capillary tube on a moving body such as an ocean buoy, would it still be able to draw the liquid upwards? Or would the turbulence slow down or stop capillary action?
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Can you tell how big a body of water is by running a current through it?

Imagine I have 2 metal cups of water. One is full and one is 10% full. Could I tell how much water is in the cups by attaching a circuit to the outside of each cup individually and getting a ...
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4answers
94 views

Fully drain water tank when it gets full with no external power [closed]

This is something I want for my home, not a scholar exercise. I have a tank that fills slowly because it is there to capture drops from a leak. This tank is on top of my house. I want this tank to ...
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3answers
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Applied: Containers without watertight cover of different height/size to be connected by a tube how do I fill them with water without overflowing?

I'm doing a bit of gardening and need help with a bit of physics. I've got 3 containers that I want to join and put water into. From which I'll fit a pump to draw water. My goal is to maximize water ...
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Why does wind blowing across a bird bath cause the water to freeze even though the ambient air temp is 39 - 40 degrees F?

Frequently, after cold frontal passage, a strong NW wind blows across the open marsh and through our back yard. With ambient temps still well above freezing, the surface of the water in our concrete ...
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3answers
159 views

Is it true that there would be no snow without dust?

I've heard from my friend that snow flake forms around the tiny dust, flying in the atmosphere. I have not found any reliable source to confirm or reject it, that's why asking here. Is that always ...
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1answer
32 views

Flow through parallel pipes with filters present [closed]

I have a system where water flow is split into two pipes, A and B. Each of A and B have a filter in the pipe. After the filter, the pipes recombine to outlet. The filters clog at different rates. I'm ...
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How can you calculate the water pressure in a sealed tank where an air bubble above the water is pressurised using a pump?

I'm trying to model a solar shower for a camper van conversion where a 17.5 litre sealed tank containing 15 litres of water heated by radiation is pressurised using a bicycle pump (valve on top of the ...
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Difference in the equlibrium of the buckets [closed]

Let there be a bucket of mass on earth resting on floor with water reaching the brim. And now consider another identical bucket with water till brim in outer space with no gravitational influence, and ...
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If we mix alcohol and water, then we heat them, will the temperature stop at 78 degree which is boiling point of alcohol?

I understand that if we heat alcohol only, the temperature will stop at its boiling point, which is 78 degree. Then the boiling point of water is 100 degree. What will happen to the boiling point if ...
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What is the phenomena where the drag of an object in water will reduce when reaching a certain speed?

What is the phenomena where the drag of an object in water will reduce when reaching a certain speed? Saw video a few years ago, kid school project, a high speed boat holding a wing under water, drag ...
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What is the total internal energy of a liter of water? [closed]

How does one calculate the total internal energy of a liter of water? For an ideal gas, the case is simple. $E = c*n*T$, where c is the molar heat capacity, $n$ number of moles, and $T$ the ...
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What's the terminal velocity for an air bubble in water?

If you release an air bubble sufficiently far under the surface of water, what is the terminal velocity of the bubble that is created? Is the terminal velocity contant or varying (the size of the ...
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1answer
36 views

What is the formula to calculate the amount of water in the air at a certain temperature and relative humidity?

I'm trying to find a formula that will give me as a result, the amount of water in a cubic meter of air. I have read this question How to calculate the volume of water in a certain amount of air, ...
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1answer
16 views

Will water introduced in a large tube connected to a small tube force water upward

Will water introduced in a large tube connected to a small tube force water upward as a self starting siphon. I am thinking of a 3"pvc pipe 6" long sealed with only a 3/8 tube coming out of ...
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Can we improve transmission of light through water?

Is there any way to add chemicals/elements to water to increase the penetration of light (em waves)?
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What is the internal energy of water vapor? OR How many degrees of freedom does $\rm H_2O$ have?

Here are the "knowns" that I'm working with. Internal Energy for a monatomic gas is $$U = (3/2)nRT$$ For a diatomic gas its $$U = (5/2)nRT$$ All of my textbooks and online sources indicate ...
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How much the water can be compressed?

How much the liquid water can be compressed? I mean the maximum achieved in practice and the maximum achevable in theory. Say for example one liter of water at 4 degrees Celsius. Can it be compressed ...
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We know a human cannot run on water, but could a much stronger and faster animal?

We know a human cannot run on water, but could a much stronger and faster animal? This viral video shows a moose running across a body of water: https://www.youtube.com/watch?v=K5-0d00hV1c Some say ...
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How to cut a pipe such that water comes out evenly across the length? [closed]

I am trying to build a wetland filter for a pond. Basically, you dig a big hole, fill it with rocks (large at bottom, small at the top), and pump water deep under these rocks, so the water slowly ...
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1answer
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How can Water exist in two different liquid states at the atomic scale?

We know how unique water is and this question is based on a recent discovery that water can exist in two different liquid states. The density of the two states vary by almost 20 %. Can someone explain ...
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1answer
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Angle of refraction of water in relation to temperature [closed]

I am an IB diploma student working with the angle of refraction of water. My goal is to note the change in the angle of refraction with temperature. However, I havent found any noticable change in my ...
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1answer
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Glass state of water

There is a lot of works on hard-sphere glasses where the spheres or other particles are squeezed and fail to find the global energy minimum being jammed in amorphous state. Is it possible to form a ...
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1answer
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Buckets of water in the cold vs ice trays in freezer

Why does a bucket of water left outside in the cold will most likely break (it happened to me; filled a bucket for cleaning intentions, then something happened and I forgot it outside - then the ...
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Will water pump efficiency change if water is pumpted into air versus underwater?

I have a water pump. It pumps water from a low spot to a higher spot. The manufacturer only recommends the motor is kept underwater at all times, and to attach a pipe size that won't slow the ...
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1answer
40 views

When pouring something on ice to make it melt at a lower temperature, does the energy required to melt it change?

When pouring something on ice, like deicing salt or vinegar, to make it melt at a lower temperature, does the energy required to melt it change (in a significant way)? Edit: I am only interested in ...
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Why can't a flame from a lighter touch water from a running faucet

I was conducting an experiment to see if my sink faucet is flammable. I did this by putting a lighter near a running facet. My first guess was that the flame will go out because of the water. But I ...
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I have a container completely filled with water, I add copper coins, how much can the water level rise before it spills? [duplicate]

My question is, how can I calculate the total volume such that once reached, the surface tension and cohesion are insufficient to keep the water stuck to the glass? I mean when we add objects to the ...
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39 views

Melt ice faster?

I had a discussion with a friend who claimed that vinegar is useful when defrosting a freezer because it lowers water's melting/freezing point. I disagreed, because I believe that the freezing point ...
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1answer
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Why doesnt a wet circuit work

I mistakenly poured water on my the area of my TV remote which has the cell and apparently the circuit connections.A thing to ponder is that why doesnt a circuit work when it becomes wet , despite it ...
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How does the temperature and humidity of air affect the water consumption of a humidifier?

We can model the water consumption $\dot{m}_{w}$ of a simple humidifier using the following equations: \begin{align} \eta_{hum} & = {T_{db,i} - T_{db,o} \over T_{db,i} - T_{wb,i}} \\ h_{o} & = ...
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Why water behaves strangely at 4 degree celsius?

The basic physics concept I hope almost every one might be aware of i.e "water tend to expand instead of freezing just below and above 4 degree celsius". My question is why exactly at 4 ...
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2answers
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Does the visible part of an iceberg depend on size?

Most people heard that we only see some % of an iceberg above water (10% etc). I suspect the exact % depends on the iceberg's shape (e.g. flat disc vs very narrow cylinder). But, assuming a similar, ...
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1answer
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How to control pitch rotation of an object that is suspended on water

I am thinking about designing an underwater vehicle. It's shape will be cylindrical(12cmx70cm). It will have a pump to pump water into a tank for adjusting density of the vehicle. In that way It will ...
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Twice the speed of water carries objects 64 times larger. Why?

From a source1 I regard as reputable, I heard the following assertion (without explanation): If the water in a stream flows twice as fast, it can carry objects (pebbles/etc) sixty four times larger. ...
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At what height does water need to fall to produce negative ions?

Research shows that waterfalls and apparently showers produce negative ions, is there a certain height or velocity for water to fall to produce negative ions?

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