What is Water: Definition and 1000 Discussions

Water is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, even though it provides no calories or organic nutrients. Its chemical formula is H2O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. Two hydrogen atoms are attached to one oxygen atom at an angle of 104.45°."Water" is the name of the liquid state of H2O at standard conditions for temperature and pressure. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of water is steam or water vapor.
Water covers 71% of the Earth's surface, mostly in seas and oceans. Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor, clouds (consisting of ice and liquid water suspended in air), and precipitation (0.001%). Water moves continually through the water cycle of evaporation, transpiration (evapotranspiration), condensation, precipitation, and runoff, usually reaching the sea.
Water plays an important role in the world economy. Approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a major source of food for many parts of the world. Much of the long-distance trade of commodities (such as oil, natural gas, and manufactured products) is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a wide variety of substances both mineral and organic; as such it is widely used in industrial processes, and in cooking and washing. Water, ice and snow are also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, diving, ice skating and skiing.

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  1. Yuvanitin

    Amount of water flowing out of a small opening

    Homework Statement: Water is flowing out through a small opening. How to calculate the amount of water that has flown out of the nozzle ? Homework Equations: I have tried solving this problem, but I am not able to. none
  2. phinds

    B Water found on potentially habitable exoplanet

    Summary: water found on potentially habitable exoplanet from the BBC https://www.bbc.com/news/science-environment-49648746
  3. A

    Tritium concentration at Fukushima Water Treatment Facility

    Hello there, maybe I am wrong but I found something inconsistent between the espected tritium concentration in Newly RO Treated Water (6.7 10^4 bq/l --> graph at pag. 16 here) and last measurement published by Tepco on 22th of August at the Water Treatment Facility (1*10^3 bq/cm3) Converting...
  4. tinakaran26

    Direct steam injection into cooling water line at pump suction

    Currently there is an operation scenario at one of our plant which directly injecting steam into cooling water line at pump suction in order to generate hot water at 60 deg C for circulation, by doing this its generate vapor at pump suction and lead to cavitation which ultimately damage pump and...
  5. C

    Why does an alkoxide steal H from water?

    So I'm watching this video on preparation of alcohol using LiAlH4: https://www.khanacademy.org/science/organic-chemistry/alcohols-ethers-epoxides-sulfides/synthesis-alcohols-tutorial/v/preparation-of-alcohols-using-lialh4?modal=1In the final step, there is a primary alkoxide. H2O moves past...
  6. Branson Sutter

    Help understanding pressure involving water in two different cylinders

    Please excuse my ignorance. I work for a Natural gas company and have an issue that needs addressed. When gas comes out of the ground it goes into a piece of equipment that separates the water from the gas. The gas goes into a pipeline and the water is dumped into a tank. We are currently trying...
  7. ValeForce46

    Water inside a pot of copper (Thermodynamics problem)

    I tried to write down the equation of heat exchanged: ##Q_{Cu}=m_{cu}*c_{cu}*(T_f-T_0)## for the pot and ##T_f## is my unknown. ##Q_{H2O}=m_{H2O}*c_{H2O}*(T_e-T_{H2O})## where ##T_e=100 °C## is the temperature of vaporization of the water. But ##Q_{H2O}## is not all the exchanged heat by the...
  8. ValeForce46

    A cylinder full of water with two holes at different heights

    This is what I did: I know that ##v_1=\sqrt{2gh_1}## and ##v_2=\sqrt{2gh_2}## thanks to Bernoulli's principle. Using equations of parabolic motion I get ##h-h_1-\frac{1}{2}g(\frac{d}{v_1})^2=0## and ##h-h_1-\frac{1}{2}g(\frac{d}{v_2})^2=0##. This means I have two equations in two unknowns...
  9. ValeForce46

    Fluid dynamics problem -- Filling linked cylinders with water

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  10. S

    Municipal water lines in cold climates - history of technology?

    In the USA, the usual solution to keeping water lines from freezing is to bury them. In cold climates this implies digging deep trenches. (On another forum, a person from Minnesota said water lines are typically buried 7 ft deep.) In the days before modern excavating equipment, were...
  11. T

    Pressure of captured air under water

    For a construction I am building, I am stumbling on a rather basic physics question regarding pressure. Let's say I have a cubic bucket of 1m^3 that I place upside down on a water surface. I add a downward force (weight) of say 1000N submerging the bucket under water with the air captured...
  12. L

    Is the initial dark carbon water from a purifier safe to drink?

    Please see attached pictures. Whenever we replace the right cartridge (with carbon filter) with new one (every 6 months). There are initial dark tint water from the carbon that fills a basin. Are the dark water safe? We throw the water of course. But there maybe those who didn't know or have...
  13. snoopies622

    What causes that water kettle sound?

    When I turn on my water kettle, I hear that familiar "hush" sound as the water heats. What exactly is that? The surface of the water vibrating? Warmer, expanding air leaving the kettle? I know it can't be a function of the water temperature itself because when I turn the kettle off the sound...
  14. somasimple

    Is There Software Available to Display Hydration Shells?

    Hi, Is there Hydration/solvation shell software? I mean softwares able to show ions/molecules and surrounding water molecules forming hydrations shell? https://en.wikipedia.org/wiki/Solvation_shell
  15. C

    Spinning a bucket of water in a vertical circle - Inertia

    Homework Statement: How or why does inertia caused the water in a bucket not to fall out when spinning in a vertical circle. Homework Equations: Is the bucket catching the water? I know Inertia is the resistance of any physical object to any change in its velocity.
  16. C

    How does inertia cause the water to stay in the bucket

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  17. C

    Physics - Spinning a bucket of water in a vertical circle

    F = mac = (mv2 / r)
  18. H

    I How to collapse a water wave through a double slit into particle behaviour?

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  19. gazaah

    Vacuum suspended fishtank: Why would this design work or not?

  20. jisbon

    Calculating Density Using Upthrust and Drag Force in Water

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  21. R

    Would a longer lever require less force to hand pump water? (PHOTO)

    I think that it would take less force to pump water based on the lever principle. But I'm not so sure! Here's a drawn photo.
  22. R

    Friction of Water Pumped Into 6in Tube from Chamber

    This is a deep well & the dimensions of the bottom chamber is 5x1x5ft which holds 187 gallons. The pump is located in this chamber with a piston/plunger only going up to the top of this chamber at 5ft. The pump pushes 187 gallons into a 6inch diameter pipe which is 1000ft long = 1,470 gallons...
  23. J

    Source strangulation for an instant water heater?

    Got an electric water heater in my flat, one of those instant ones. It outputs a low flow but this is alright as you mix the hot water with cold water in the shower. Problem is, in the summer you need to mix in too much cold water in the shower and the heater shuts down, probably as it senses...
  24. R

    If this hand water pump was instead at the bottom of a well....

    Read summary
  25. P

    Force on Dam: Height or Amount of Water?

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  26. M

    Water Freezing in Space: Debunking the Myth of Instant Boiling and Freezing

    There's no thermodynamics forum, so I'll post this here. Things "freezing" in space has always bothered me ever since Tim Robbins removed his helmet while in orbit around Mars...
  27. Don Bori

    Water Tank Refilling via Hydraulic Water Pumping System

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  28. T

    Why is this water turning black during electrolysis?

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  29. fernelau

    Understanding the Impact of Convex Lens Focal Length on Water Temperature

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  30. person123

    MATLAB MATLAB API For Wave Flume Data Analysis

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  31. J

    A Negative Pressure in Solid Phase Diagram of Water

    Hi everyone! I am working with the theoretical solid phase diagram of water and I would like to know what negative pressure means. Thank you in advance!
  32. G

    Why does 32 F ice have more energy than 32 F water?

    Why does 32 F ice have more energy that 32 F water?
  33. DaveC426913

    The ol' water going down the drain thing

    Split off from here: https://www.physicsforums.com/threads/what-is-responsible-for-the-spinning-of-a-galaxy.974218/#post-6201131Has the idea of Coriolis force affecting the direction of swirl down a drain been compellingly vindicated or debunked? I don't mean in theory. We all know the theory...
  34. D

    Electrical Enclosed water turbine power generation

    In theory or at least in my head, it seems simple enough to me. A simple water pump, such as a pool pump pushes water through a pipe into a water turbine and recycles the water directly back to the pump. With some of the hydrogenerators I've seen out there, they produce far more power than the...
  35. J

    Motion Q: Dropping/Throwing Stone in Water-Vi, Vf, a, t, d

    What I know for Number 1. t=2.7s d=? Vi=0m/s^-1 a=9.8m/s^-2 Vf=? Equation to use? Vf=Vi+at= 0+9.8m/s^-2x2.3= 26.46m/s So for number one the final velocity is 26.46m/s d = 0.5 * g * t2 = 0.5x9.8x2.7^2=35.721 Number 2 I know t=2.3s d=35.721 vi? Vf? a=9.8? what formula do...
  36. K

    Finding the average water mass flow rate in a water rocket

    Could anyone kindly kind me as to where this formula is derived from and how, because I searched and can't find it anywhere
  37. Parzeevahl

    Entropy change for water in contact with a reservoir

    Problem Statement: 1 kg of water at 273 K is brought into contact with a heat reservoir at 373 K. When the water has reached 373 K, what is the entropy change of the water, of the heat reservoir, and of the universe? Relevant Equations: dS=Cp*(dT/T)-nR*(dP/P) dS=Cv*(dT/T)+nR*(dV/V) I am...
  38. didaw

    Calculate the force on the side of this water storage box

    Area = 1 x 0.5= 0.5 1st moment of area = 0.5 x (0.5/2) = 0.125 m total force = p x g x 1 moment = 1000 x 9.81 x 0.125 = 1226.25N Force = 1226.25 im pretty sure all that is right i think the second moment = Ix = bh^3 / 3 = 1 x 0.5^3 / 3 = 0.0416 then 2nd moment of area / 1st moment of area...
  39. J

    Adding xylitol to hot water lowers the boiling point and makes it boil

    This probably occurs with salt too but let's concentrate on xylitol: you heat water till it boils, put the hot water in a cup and add a tsp of xylitol. It boils again violently for a couple of seconds. The high school explanation is that the boiling point of the water is lowered. I'd like to...
  40. C

    At what wind speed will salt water "boil"?

    During hurricane Lenny in 1999, I was anchored on my sailboat in a protected cove in the Virgin Islands. The winds were about 60 mph with gusts to an estimated 80 mph where we were. I observed that during the gusts, the salt water would "boil", that is, totally evaporate the surface into a cloud...
  41. Spinnor

    Plumbing Stainless steel house water filter, leaks past o-ring

    Bought a stainless steel whole house water filter for a very good price ($100), turns out too good. On inspection I suspected it would leak so rather then installing it into the house water system I pressure tested it. There was a small leak that stopped after a minute or so. Relieve the...
  42. V

    Calculating Work and Velocity on a Water Slide

    I don't really understand if the initial horizontal velocity is 0? Or do I assume it's some constant? Putting aside vertical velocity. Also how should the "mechanical work done by gravity" be calculated? Is it just ##W = \frac{1}{2}mv^2_{final} - \frac{1}{2}mv^2_{initial}##
  43. Zouatine

    Minimizing the area of a channel in contact with water

    My problem: In the solution,our teacher found, that the wet section is minimal if y=L/2 So Am: = L^2 /2; Pm: = 2L; So despite that I try with any value, I can not find a more minimal section, and that's not the case because if I try with y = L / 3 I find Am: L^2/3; Pm: (5/3)*L ; and these...
  44. J

    Water pressure question involving pipe, flexible hose and a filter

    Summary: water pressure issues what happens when you take water from a 3/4 inch pipe copper to 1/2 inch flexible braided hose through a filter for a 3/4 pipe back through a flexible braided hose 1/2 inch tube to 3/4 inch copper pipe?
  45. S

    Will Water Levels Equalize in Two Connected Tanks Despite Pipe Friction?

    I know that water losses pressure as it move throw a pipe due to friction. Does that mean that if we have two elevated tanks separated by a great distance but connected throw a perfectly horizontal pipe ,and then we fill the first tank with water till it reaches a certain hight, then the hight...
  46. E

    How long will it take to boil 1 liter of water?

    Hi. I have been trying to solve the following problem:How long will it take to boil 1 liter of water from 20°C? The heat efficiency / η is 85% , voltage / U 230V and power / P 200W. The answer must be given in seconds. So, t1 = 20°C t2 = 100°C Δt = 80°C V = 1,0 liter → m = 1,0 kg...
  47. N

    How to calculate change of velocity after hitting water?

    Me and a Partner are presenting the physics of diving as our final in physics. He wants a ton of detail about the activity we choose so I thought it would be a good idea to show the difference from a cannonball vs a normal dive and the change in velocity that occurs with both, and also how much...
  48. R

    Possibility of using a UVC LED to disinfect water?

    Hey everyone, I recently came across UVC leds and was wondering if they could be used to disinfect water in a simple way. If I got a bucket with 5 litres of water in it, stuck a 50mW radiant flux UVC led (like this) on the lid and run it for 1 minute would that be enough time and power to...
  49. J

    Electrical Solar to Hot Water Heater Hookup

    If one hooks up solar panel to bottom element after removing AC line seemed like good idea then I was wondering if the wires going to the element will get hot instead of the element see drawing.
  50. D

    Rank the faces in order of decreasing water pressure

    I assumed that the same magnitude of force acts on all sides of the box. Since A had the smallest area, I ranked P(A) as having the largest pressure, followed by P(B) having the second largest and P(top) and P(bottom) having the same pressure at third largest each. However, the ranking I...
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