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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Fluid mechanics - Transport Phenomena [closed]

Could someone guide me in this resolution? As the air that will be used to obtain hospital oxygen needs to be free of particles and water, before going to the heat exchanger to condense it must go ...
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Why does wetting something change its colour? [duplicate]

I have noticed that wetting something almost always changes its colour. For example sprinkling water onto a t-shirt creates darker spots on the fabric; but this effect is not limited to fabric, almost ...
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Floating garbage collector [closed]

I am trying to build a floating garbage collector. The concept isn't that hard, but when it comes to the math and physics it's beyond me. The idea is a floating bin that allows the garbage to fall ...
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Morison Equation - Value of $k$ not working

Need a hand with the Morison Equation with $k$ giving me a headache. I'm following a video online trying to calculate the force on a structure I am designing for work. I try to follow videos using ...
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Water stream bending to electrostatic charge

Why does the water stream really bend towards a charged comb? I share an hypothesis that the 1000's of YouTube videos and similar number of scientific and scholastic articles presented as proof of the ...
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How come the filled water bottle work as a stylus for phone but not the empty bottle?

Take an empty plastic bottle, and make it slide on a mobile screen. You would find that it's not doing anything. Now filled up this bottle with water and try doing the same. This time you will find ...
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How to maintain moisture on a substrate?

I know that different materials absorb water differently and dry differently. The simplest example is when washing clothes and putting them in the dryer they take different amounts of time to ...
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Why can't water be liquid above 647 kelvins?

In this article about vapor, it is said that liquid water can't exist if its temperature is higher than 647 kelvins. But if we put the liquid water in a closed container and heated up the water, ...
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Is steam just a combination of small waterdrops and air?

I have seen a question here about steam. It made me unsure about the nature of steam. Isn't steam a hot white cloud of water vapor? Is it just water in a gas state, so that its temperature can be ...
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Why do we “feel” steam at 100 °C as hotter than water at 100 °C?

A block of ice as big as a room will have more thermal energy than a cup of hot tea. But the tea feels hotter because the average kinetic energy (temperature) is higher in case of tea. I conclude from ...
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Is supercooling water reversible?

Water can exist in a supercooled state. Even at $-48,3$ degrees Celsius it can be liquid. Below that temperature, the water will freeze. If I cool the ice to, say, $-60$ degrees and heat it slowly ...
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Can ice patterns form on the top of deep water?

Here is a picture of a pattern in ice: There are feathers, or flowers to be seen. The ice has grown on a solid underground. Water condenses on the solid underground and freezes. I have never seen ...
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Force required to pull a floating object under water relative to mass and volume

Let's say you have multiple objects with the same density floating on top of the water but they have different volumes and masses. Does it take any more force to pull the different objects under the ...
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Why do objects appear larger in water? [duplicate]

Why does it look bigger when we see something in the water?
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1answer
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Latent heat of water at triple point

My class textbook states that the latent heat at triple point of water is zero. When i tried to look up there was less to no information about this fact. Can anyone give any plausible explanation for ...
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Blood flow problem using the continuity equation

Blood flow increases during exercise by the dilation of blood vessel diameter together with an increase in blood pressure. Suppose that the flow rate increases by a factor of 4.5 and blood pressure ...
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How many water molecules should I put together before I can tell If it's liquid, gas or Solid?

How many water molecules should I put together before I can tell If it's liquid, gas, or Solid? I know, there isn't any clear boundary that says that you have to put $50$ molecules or $100$ ...
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Formation of water droplets

Suppose several small water droplets are formed from a big blob of water at room temperature. Will the temperature of resultant water droplets or the surrounding air decrease? Consider it as an ...
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1answer
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What happens to water pressure if diameter of the tube is increased?

Suppose that I have a syringe piston, connected to a closed sample cell through a 3 mm diameter stainless tube (SS). Its like syringe, ss tube, sample cell; all are connected in line with fittings. ...
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How to calculate the range of fluid spray?

I need to calculate the range that a fluid (water in this case) will travel after exiting a nozzle. The water will be sprayed through the air from a height of 2 m at a horizontal angle. The exit ...
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Why are the tops of mountains covered with snow, but not at the bottom? [duplicate]

Why are the tops of mountains covered with snow, but not at the bottom? There is always snow even on high peaks in very hot areas. It has to be very cold at the top of the mountaintop so that the snow ...
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If heat is supplied to a system consisting of water and ice at 0 degrees Celsius, which will absorb heat first and what is the underlying physics?

I am supposed to answer this question in terms of the Zeroth and First Law of Thermodynamics. So, I wrote this: “If heat is supplied to a system, the system will absorb the heat first. In this case, ...
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Is drinking water an important feature for finding habitable exoplanets? Has it been found?

We need drinking water to live on other planets. Has drinking water been found on other exoplanets? Is drinking water an important feature for finding habitable exoplanets? I want to (self) study in ...
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Water pressure at the base of two different sized cylinders [duplicate]

Will the water pressures at the base of two different sized cylinders be the same if they are filled to the same height? Sorry for crappy drawing
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Positive correlation between temperature and refractive index of water?

I am currently doing an experiment on refraction for physics class where I am looking at the relation between refractive index and temperature of water. The result I got was the the refractive index ...
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Effect of bends on the radiation pattern in monopole and dipole seawater/liquid antennas (Reference Request)

I'm aware of the radiation pattern and the electromagnetic theoretical analysis behind monopole and dipole seawater/liquid antennas (cf.Investigations of Water-Based Liquid Antennas for Wireless ...
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1answer
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What can cause different levels in communicating vessels?

I have three small tanks connected by a 6 mm pipe. The pipe fits into an hole made at the bottom side of the tank. Pipes are connected at the junction point using a T-shape connector. Here a drawing ...
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What is the formula to determine the change in pressure when there is a change in flow?

[Updated to help clarify my question] I have a current water flow of 9 GPM (gallons per minute) at 50 PSI through a 1/2 inch diameter pipe pouring out at the end. I understand that if I reduce the ...
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My fish pond I was wondering if the water will evaporate quicker with the water fall running and blowing air into the pond with an air stone

Hi I keep thinking that my pond has a leak I have just emptied and cleaned the pond and made sure there was no leaks as I could see. When running the pond water is being pumped through sealed ...
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Temperature differences [closed]

Suppose, there's a waterfall. Water is falling from 100 meters above. So, what's the difference between top and bottom's temperature difference? (Using Google Translate : A waterfall falls below the ...
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What is implied by the term “phase transition” as in when you boil water?

I have somehow gathered that when you heat water as you record its temperature, it's temperature begins to rise until it boils. After that it's temperature will not rise by adding anymore heat. So ...
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Do water droplets falling from the sky product roughly pi total waves?

So I was making an observation outside while it was raining on my porch, the droplets roughly made 3 total cycles of waves. I made a hypothesis that the total wavelength from beginning to end might be ...
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What would happen if all water on Earth froze instantaneously? [closed]

What will happen if all water on the surface of the Earth froze instantaneously? Let's take into consideration only the non-frozen part of the oceans, which comes close to all water on the surface. ...
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Could the hypothetic water bodies on Mars be 'stable' only if they were large like Earth's oceans?

Could the hypothetic water bodies on Mars be 'stable' only if they were large like Earth's oceans which needs macroscopic basins? Are possible rivers and lakes enough to ,mantain all the water.As ...
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Is the buoyant force of air implicitly neglected for an object half-inmersed in water?

I saw in this answer that the atmospheric pressure is conveniently canceled mathematically when taking the atmospheric pressure at the level of the top of the object. However, when I was inventing ...
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What's the pressure inside a barometer?

I have the following problem I'm trying to solve. Let's say we have a barometer filled with water as in the following diagram: The question to be answered is what's the pressure $p$ on the inside of ...
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When putting a floating object in water, why the displacement of mass of water is not equal to only the part of the object inside the water?

In this question Will a bathtub full of water weigh more if I add something that floats in the water? the marked answers mentioned a special case where the bathtub is full to a brim and the boat is ...
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Is there a reason for snow to be white, in connection to it not melting under bright sun?

I've had this thought for a long time and finally decided to ask if anybody else has thought the same. There are a lot of places on Earth where snow lies and doesn't melt under bright sun, because it ...
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What the air pressure inside an air bubble in water [closed]

I am a newbie in physics and have a homework problem, I hope I am not asking something stupid, since I don't learn physics nor am I going to do anything advanced with it. So let's say we have a bubble ...
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What is the diff in operational range underwater between a dipole trimmed to resonate @2.45GHz versus a dipole tuned to resonate using a pi network?

(Sorry about the use of "diff", but I needed the characters.) In air, a half-wave dipole can be physically trimmed to resonance and will radiate well. It can also be tuned using a pi network ...
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Problem involving concentration of solution with inflow and outflow

A question describes a tank, initially with 50L of pure water, with 2L of brine solution(at $5gmL^{-1}$) flowing in per minute, alongwith 1L flowing out per minute(the mixture's kept uniform by ...
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Hydrogen bonding as a function of $kT$

The strength of a hydrogen bond in water at ambient conditions is about $8kT$, where $k$ is the Boltzmann constant and $T$ is the temperature. So why do hydrogen bonds form and break so readily in ...
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Why do we cool water with ice? [closed]

I've came up with the following question: Why do we cool water with ice rather than with steel given that the last one has a bigger thermal conductivity?
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Why was water freezing almost instantaneously when shaking a bottle that spent the night outside during a frosty night?

Due to the forecasted frost last night, I placed yesterday evening, some 1.5l standard PET bottles filled up to 90% with warm tap water(+60°C) close to some vegetables that I wanted to protect in my ...
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How do I calculate equilibrium temperature of a pot of water with some food in it, knowing only the equilibrium temperature of the pot of water? [closed]

Say I have a pot with 3L water on a stovetop, at an equilibrium temperature of 75ºC. I then add 1kg of meat at 20ºC to it. How do I calculate the final equilibrium temperature I should expect the pot'...
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Behaviour of water as pressure increases to infinity [duplicate]

Original Question Source: Water behaviour under theoretical near-infinite pressure conditions Here's the phase diagram for water: The diagram shows us that at pressures around 1 terapascal (about 10 ...
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In a sealed chamber, can a vapor be heated enough, that the pressure increases enough, to condense to liquid?

Assuming a sealed chamber, containing a vapor, where volume is constant: Given that the ideal-gas law states $PV = nRT$, if heat is added to an ideal-gas, the pressure will increase as a function of ...
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Why does water easily absorb THz radiation?

It is stated that water is extremely sensitive to THz radiation, absorbing big amounts of this radiation, this being a reason why skin measurements are safe to do using this range of frequencies (1) (...
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Can water thermolyse in significant amounts?

According to Wikipedia water can thermolyse starting at around 1200 celcius, though the auto-ignition point of hydrogen is at around 535 celcius. I'm wondering in what sense water actually even ...
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Water pressure calculation from overhead tank to treatment plant

I have an overhead water tank which is at a height of $38'$ from the ground level. I have a water treatment plant at ground level to which we need to provide a water line from the overhead tank. ...

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