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. solarcat

    Water Slide Physics: Solving for Angular Momentum, Velocity, and Energy

    First I found the moment of inertia of the rod + rider to be I = (70 kg * 62 m2+ 1/3 * 24 kg * 62 m2)= 2808 Then I found initial angular momentum of the pole and rider just as the rider grabs the pole: L = Iw = 2808 v0/ 6 m = 468 v0 Then I found the final angular momentum of the pole and rider...
  2. D

    How to find the velocity of a water leak in a spinning tank

    We have a cylindrical water tank that spins over its axis of symmetry with constant angular velocity ω. Here's a diagram: We wish to find: 1 - The tangential and radial components of the velocity of the water as it leaves the tank. 2 - The radius r reached by the water. I'm not sure at all...
  3. T

    Pressure in a water heater - does it depend on size?

    Picture two water heaters - one 10 liters and the other 100 liters, initially filled with cold water. If both of them are heated to the same temperature, will a pressure meter display the same pressure for both tanks, or is the resulting pressure somehow dependent on the size of the tank?
  4. lekh2003

    Why does salt reduce the freezing point of water?

    I've been looking into how adding sodium chloride or calcium chloride to snow reduces the freezing point, and why this occurs. The really simple reason I found on this website: https://www.thoughtco.com/how-salt-melts-ice-3976057 , which simply stated that the salt ions get in the way of the...
  5. T

    Calculate the Force Required for a Wave Generator in a Water Flume

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  6. R

    Circulation of water in a cylindrical reservoir

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  7. BillTre

    I Is Late Water Flow on Mars Linked to Climate Change or Permafrost Melting?

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  8. S

    Water jet strikes a plate and slows down due to frictional forces?

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  9. B

    How to measure water flowing from a washing machine pump?

    Hi all Am trying to find a way to measure the vol/time flow of water from the washing machine. Is there an electronic component that can be used like a coil of copper wire over the tube and the do something with a microcontroller perhaps and it figures out much flow? by electromagnetic...
  10. A

    Electrical generation from used water in my home

    Hi everyone. I was just out in my back garden and was watching the water from someone's shower pour down the pipe and out into a drain. I was thinking if all of the used water from my house just goes down a drain then why not try make use of it. If the water system continues after use and takes...
  11. T

    Maximum height for water from a fire hose

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  12. patric44

    Calculating the Length of a Water Column in a Beaker

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  13. R

    Reduction in gas concentration of water with solutes

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  14. J

    Electrical Electric Hot Water Heater 2000 watt 220 volt run on 110 volt

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  15. C

    Comparing Water and Ice Melting for fighting fires

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  16. C

    Does temperature increase when water is boiling at 100C......

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  17. Dave Burch

    Frozen Olive Oil compared to frozen water

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  18. LordGfcd

    A fluid mechanics problem -- Shape of a falling water drop

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  19. Roy S Ramirez

    How can I predict the flow rate for a real life water hose?

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  20. V

    How to determine the volume of water to add to a dried primer

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  21. C

    Tracking Spread of a water jet out of a downward-facing pipe

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  22. callie123

    Writing: Input Wanted Electrified Water: Feasibility and Applications

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  23. M

    Water vapor absorption in THz range

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  24. I

    Force exerted by a deflecting water jet

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  25. sophiecentaur

    Absorption rate of CO2 in water

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  26. A

    Misc.  Develop Water Pressure Powered Motor | Tesla, Terry, Vane or Pelton

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  27. S

    Exploring Conservation of Energy: Ball Dropped in Water

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  28. S

    Gas Solubility in water - constants, and calculations

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  29. D

    Misc. Hydrostatics problem in a water vessel

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  30. J

    Determining Solubility in Acidic Solutions / Pure Water

    Homework Statement How many of the following would you NOT expect to be more soluble in acid than in pure water? FeS, CuCN, AlPO4, BaCO3, AgCl Homework Equations None necessary The Attempt at a Solution So we know that anything with OH- or anything that has the conjugate base of a weak acid...
  31. M

    Help with Chemical reactions that make water unstable....

    Directly without any introduction _ I really want some help from chemical engineers I was just looking for some chemical reactions that can make water unstable like when we put it in the water the water will move will not be stable or in an equilibrium state thank you very much
  32. A

    What are the materials and methods for testing plastic levels in water?

    On wikipedia (https://en.wikipedia.org/wiki/Iron(III)_chloride) it says: The ferric chloride test is a traditional colorimetric test for phenols, which uses a 1% iron(III) chloride solution that has been neutralised with sodium hydroxide until a slight precipitate of FeO(OH) is formed.[26] The...
  33. A

    How Long Will It Take A Tank Of Water To Warm to 70 Degrees

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  34. doglover9754

    Why does water not follow the law of motion?

    So I was in the bus going to school. I sat in the back not directly underneath the emergency exit but more like behind it. Anyways, since it’s been raining consistently, the emergency exits sometimes leak. So I’m sitting down and my jacket sleeve gets wet with a drop from the emergency exit. I...
  35. C

    Flow of Water into a Bowl with Holes

    I'm facing a problem with that rhyming title up there. The design is thus: a downward-facing, vertical pipe with known constant flow and diameter has water flowing out of it, into a short (15cm-91cm) free fall. At the end of that fall is a bowl of indeterminate depth made of steel with holes...
  36. O

    MCNP neutron energy deposition in water

    Hi, I did an MCNP simulation to see the neutron energy deposition in water. I used 14-MeV neutrons, and big enough water body to make sure all the neutrons stay in the water and give all their energies to water. I used F6 tally. However, I got energy deposition of around 10.3 MeV, not 14 MEV...
  37. gpowell

    Energy requirements for creating water mist

    The basis of the question is: in creating a mist that you sprayed on a surface could you get an energy transfer to the surface equivalent to an optical emission in the infrared? (Far Infrared). How much energy is imparted to room temp water in creating a spray of particles around 5 microns...
  38. S

    Sound Wave Problem -- time of flight in air versus in water

    Homework Statement Homework Equations v = d/t Solve for t. t = d/v The Attempt at a Solution In my General Physics 2 course we are doing sound waves I have the answer to the problem which is 90.8m I am trying to understand the concepts of sound wave. So please correct me if I am wrong, 1...
  39. P

    Calculating the mass and price of LPG needed to heat water

    Hello everyone, Homework Statement How many kilograms of lpg will you use if you heat 5 litres of water from 20C to 90C everyday for 30 days and how much will that cost if a 12.5kg cylinder is 1750 Rupees The attempt at a solution To heat 1 liter of water by 1C requires 4.18kJ so you then...
  40. S

    Balance reading when new object immersed in water

    Homework Statement The weight of a glass full of water is being measured using balance. a. An object is fully immersed so that some of water spilled out. How is the reading compared to before the object is immersed? b. If the experiment is repeated and now the object immersed has same volume...
  41. jappy190

    Calculating charge density of particular ligands

    Hi everyone, this is my first thread! I am currently undergoing a personal investigation that is based on one of the factors which effect the splitting of d orbitals in central metal ion by the charge density of ligands (in a complex ion). However, recently I got stumped by trying to...
  42. R

    Oil-Water-Salt - What's the force at work here?

    Hi, This is something I observed in the kitchen when I was cooking something. I had put some water in a vessel, to which, I added couple of spoons of oil. The oil formed large droplets on water surface. I then sprinkled normal table salt crystals on to the water surface and they sank to the...
  43. D

    Determining the flow rate for a cooling system

    MODERATOR'S NOTE: HOMEWORK INCORRECTLY POSTED TO CLASSICAL FORUM, SO NO TEMPLATE I need help with the following question: Please have a look at the question and my attempt at the solution. Alternative cooling systems are considered for a large computing centre requiring 1 MW of cooling...
  44. P

    How will melted ice in a pool change the water level

    if I have a pool that is 20x20 surface area and I put a 200 gallon block of ice it, the water level will go up by X amount. when it melts how much will the water level change?
  45. F

    Why does water evaporate when it's less than 212 F outside?

    When one boils a pot of water on the stove, the water starts to boil into steam at 212 degrees Fahrenheit. The stove provides the heat both to make the water 212 degrees, and the stove provides the heat to change the state of the liquid water to vapor. However, we all know that water (or any...
  46. PainterGuy

    The speed of light in glass and water

    Hi, The speed of light is given c=1/√(ε0μ0) where ε0 is permittivity of vacuum and μ0 is vacuum permeability. The permittivity and permeability of a material is given as ε=εrε0 and μ=μr)μ0 respectively where ε is absolute permittivity of the material and εr is relative permittivity of the...
  47. A

    Understanding Internal Energy: Exploring the Role of Volume in Thermodynamics

    Good day all ! I have a confusion regarding the use of the formula dU=CdT for computing internal energy for liquid or solid like for instance in this exercice We have an isothermal process so I thought that dU=0 so according to the first law of thermodynamics dQ=-dW (we want to calulate the...
  48. N

    Why does the lion look inverted in the water?

    Hello (This image is taken from Physics textbook grade 10. The book has been published in Pakistan) My question is: why do see the lion inverted in water in this image? I think it is due to the process of continuous reflection. But I am not sure. I need your help. Thanks.
  49. R

    Find the initial velocity of a water rocket (mass changes)

    Homework Statement Find the initial velocity of the boost phase (when water is coming out). Here is everything I know - Mass of rocket with no water is 0.13kg, mass of rocket with water is 1.1kg. The total length of the rocket is 0.48m. The time to the maximum point is 3.46 seconds, and total...
  50. P

    How the forces on a drop of water versus mercury on a glass slide influence the shape?

    I am trying to understand how fluids form particular shapes when put on a solid. In the two figures,what are we taking as a system for the forces? How the resultant of the forces influences the shape of the different fluids?
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