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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2answers
23 views

Detailed Explanation Wanted - Bell Siphon

Alright, so I'm trying to understand in detail what occurs the moment the water covers the outlet tube in a bell siphon. Most sources hand wave and just say "SIPHON HAS OCCURED" or "...
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Atmospheric pressure vs. boiling point equation

What is the relationship between the pressure of water and its boiling point? I am aware that a substance boils as soon as its vapor pressure equals that of the surrounding air. I have researched ...
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Surface tension in a water drop

Consider the above image This is a pretty standard diagram but it makes no sense to me. I have some questions regarding it. Why are we taking surface tension of air-solid interface into consideration ...
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1answer
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Pool cover efficiency of absorbing and retaining heat in pool water

Looking into the options of adding and retaining heat in the outdoor pool (and saving wallet) - heat inverter, roof solar water heater, gas heaters etc. the pool cover seems to rule them all (at least ...
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Can you explain the meaning of buoyancy, written here?

I got this Archimedes' principles from a website named smithplanets.com Can you explain why we cut the volume of water equivalent to the weight of an object when the object is floating in the water ...
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How do buoyancy and pseudo forces combine?

About the diagram: A tennis ball is attached to a string which is attached to the jar. The string is mass less. The density of the ball is less than that of water. The F.B.D of the tennis ball: Thus ...
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Earth doesn't have seafloor craters. Does it mean water has been on Earth since long time before in the past?

Is it true that Earth didn't get its water by cometes impacts as there are no subocean craters so it seems water acted as a comete bumper long before in the past?
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Can non-harmful eddy currents be used to heat water? [closed]

I think after 'googling' some web sources that eddy currents are strictly localized in a volume of iron surraunded by a loaded inductive coil so can not cause an electric shock to a person while the ...
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Amount and percentage of water in air

I was wondering about the relationship between the amount of water in the air, and the percentage. Is the following correct? Let's take an example of 20⁰C. According to this page air at that ...
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Heating water manually

Is it possible to heat a small amount of water, may be a cup of it, only by human force, using a small scale version of a device like Joule used to prove the heat mechanical equivalence, just by inner ...
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1answer
33 views

How much buoyant force to pull a plastic cube from under a tank of water in to the water?

I'm having a hard time to understand how many same size black cubes would be in order to pull up the bottom black cube in to the water. I know water level is important but I believe there must be a ...
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Forcing freezed water to become a ferroelectric?

I got answers a long time ago about the possibility to make of iced water a permanent ferroelectric.This means put the water in a box and apply a strong electric field and in that condition let the ...
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Can water produce light when heated?

I am asking this regarding blackbody radiation. Water is not black, obviously. I read it is very lightly blue, but it is mostly transparent in liquid form so it probably does not absorb much of the ...
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Are water molecules orientation absolutely independent of the flow direction?

Or is there a bias toward a specific angle in regards to the direction of the current?
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Does water produce electromagnetic radiation when it moves?

Since water molecules are dipoles and get excited by microwave radiation I wonder if the opposite is true and water can act as an electromagnetic emitter.
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When pressing coffee, why does boiling water and coffee mixture appear to decrease after grounds are pressed to bottom?

When pressing coffee, why does total volume of boiling water and coffee appear to decrease after grounds are pressed to bottom?
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How much can water compress air?

So I was thinking of using a barometric sensor to measure the compression of air in a tube in order to measure water level in a tank (Basic diagram below). So based on the equation $ \frac{P_1 V_1}{...
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How deep does the pool at the end of a waterslide need to be?

I am looking at a problem where a woman has travelled down a simple waterslide and into a pool, then hurt her knee by striking the floor of the pool. I need to figure out how deep the pool needed to ...
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Add salt before or after boiling water (energy issue)

Some time ago after discussing with my cooking friends I came up to a question: Q: What makes water boil faster, adding salt a the begging or at the end of boiling? A: Briefly, adding salt before ...
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Does increasing the circumfrence of a wall around a pond increase the pressure against the wall?

I have a wall that forms a circle around a pond. It is 3 bricks high and 10 ft in diameter. It is made of bricks that weight 20 pounds. ...
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How does the kinetic energy of a falling object affect the wave amplitude?

Which formulas would be useful for this problem? assuming that all the energy is transferred from the falling object to the water waves. The kinetic energy of the object would be transferred to gpe of ...
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Is there a frequency to which electromagnetic radiation would make an entire ice cube (or another material) vibrate?

Microwave oven radiation makes water molecules rotate. I just wonder if there is a wavelength, supposedly related to the lattice of water ice, molecules spacing, whatever, that would set the entire ...
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Relationship between density of water and temperature

How can I find the different temperatures of the water with the same density? Eg, At approximately what other temperature does water have the same density as at 1∘C?
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Does the Mpemba Effect affect none-water substances?

Does the Mpemba Effect work on liquids other than water? If so, what are the similarities/differences, and what contributes to it(mainly the differences)?
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Physics of an hypothetical animal attack (orca ramming through sea ice)

Question: Could an aquatic animal weighing 5,000 kg and traveling at 55 km/hr break through solid 11cm-thick ice? Context: I am writing a story and want the physics to be as accurate as possible. I'd ...
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1answer
50 views

Is it possible to cool down air with warm water?

Is there some condition in wich the water evaporation can cool down the air even if the water is hotter than the air?
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Viscosity equations for rockets

I'm doing an experiment about the effect of viscosity on water rockets, and was wondering if there are any equations that include viscosity that are significant to rockets/water rockets.
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Surface tension of soapwater

The addition of foreign particles reduces the surface tension between particles of the substance under observation. This is something we accept and something that makes common sense. But how do we ...
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What is the difference between the specific heat capacities of water under isobaric and isochoric conditions

Can the difference of specific heat capacity of water under isochoric and isobaric conditions be explained in terms of the internal energy of the system? Most of the videos I have watched base their ...
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While freezing ice from salt water, does the salt dissolve in the ice or is it separated out?

I know that salt decreases the freezing point of water. We have freezing point (in Celsius), $\mathrm{T_f=-K_f\cdot m}$ (molality of salt). But, is it true that all of the solution doesn't freeze at ...
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How long and how much water will boil at room temperature in a vacuum chamber

Let's say, I have a vacuum chamber of diameter D and height h. I have filled 1/10th of the chamber with water. Now I have two questions: 1.How long and how much water will boil or evaporate if the ...
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Scattering of Light by Pure Water

I'm looking for a quantitative (and accessible) description on the scattering of NIR light (850 nm) by pure water. More specifically, I want to find how much of the incident 850 nm light beam is ...
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How can I view through the water surface without reflection? [closed]

I am searching for a possibility to see the shallow grounds of water without reflections on the surface. I am sailing in an area where there are reefs and shallow coral patches which can be dangerous ...
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How do firefighting helicopters refill their water reservoirs while hovering?

I have been curious these days about how firefighting helicopters go about refilling their water reservoirs while hovering, and I was wondering, If the helicopter hovers $5 m$ above the refill ...
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Heat transfer of a water body like fish pond and lake

As an introduction, I am a computer engineering student that want to create an arduino project in which it use water temperature as its parameter. The temperature will help the microcontroller choose ...
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Enthalpy of vaporization of water and specific heat of water differences

So I am doing a lot of research on evaporative coolers and I have come to a question I can't find much info on. I am currently a mechatronics engineering student that has yet to take thermodynamics so ...
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Have water first order system dynamics or second order dynamics? [closed]

This is two transfer functions. One first order and the other is on second order $$G_1(s) = \frac{K}{1 + Ts}$$ $$G_2(s) = \frac{K\omega^2}{\omega^2 + 2\zeta \omega s + s^2}$$ The know characteristic ...
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1answer
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How to make water condensate in a specific spot in a closed container? [closed]

I plan on making a large closed terrarium with a dry area and a wet area. How do I make sure that the evaporating water from the wet area does not condense into the dry area? I have found little to no ...
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Can cooled gasses be bubbled up through water to cool it?

I'm working with a pressure vessel that is cooled to a reasonably cool temperature. Since it is cooled at pressure when the air exits the pressurized system the gas expands and thus cools a great deal ...
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Stability of hydrosols given temperature and humidity

I had always been under the impression that animal exhalations were composed of air, carbon dioxide, and water vapor, meaning individual molecules of H2O in the form of a gas. However, recently I read ...
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3answers
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Why do hose pipes move when water is flowing?

Today I left my detachable shower head on the floor and as soon as I turned the water on, the shower head started moving and getting jumpy. Onto my question- why do hose pipes move and jump when water ...
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Measuring real time water usage with live water pressure monitoring

My home started seeing high water bills recently. My water company doesn't provide live water meter readings. There is a water meter on the street which I can monitor while water is being used but I ...
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2answers
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Why has warm air a higher water saturation than cold air?

I've wondered about that for a while but all I read is commonly just "Warm/hot air has a higher energy so when it hits the surface of a liquid, it has a higher probability to transfer energy, ...
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What gets warmer faster: icewater or just ice? [closed]

Revised Question (07/07/20 14:00 UTC) Working off of a suggestion by @GiorgioP: "Would it be fair to say that your question is about the difference of melting behavior of ice if surrounded by ...
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How much energy is required to boil and maintain boiling water temperature for a set time period?

I am trying to calculate the amount of energy required to bring 1 litre of water up to boil (from 20 degrees C to 100 degrees C) and to maintain the water temperature at 100 degrees C for a period of ...
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How does water move out of the way/around an object moving under water?

Let's say a torpedo moved under the water. Water is virtually in-compressible right? So what happens to the water in front of the torpedo as it pushes forward? It has to somehow move out of the way, ...
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Is possible to determine the water flow rate of this pipe with only geometric informations?

We have this water tank ($R$) that is pumping water to the end of pipe ($E$) in this figure. When I say geometric information I mean things like: area of the pipe section, height of the reservatory ...
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1answer
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Why does the pressure inside a pipe momentarily increases when the tap is closed?

I fill coolers in my house with a pipe connected to a tap, as soon as it is full i place a thumb on the open section of the pipe effectively shutting off the outflow of water. Keeping my thumb in ...
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How does the width or depth of a container of water affects the speed of an object (e.g. a toy boat) travelling on it?

I am planning to carry out an experiment to investigate how the distance between an object travelling on water (i.e. a toy boat) and the walls would affect its speed. I predict that the speed will ...
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Eternal looping water tap

If i have a container like this (filled full with water): and I unplugged the small tap, would the water pressure be big enough to blast the water to the right side of the container and cause an ...

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