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.

View More On Wikipedia.org
Recent contents Top users
  1. A

    Energy absorbed by water illuminated by an LED source

    Good morning, I was wondering if I am thinking correctly. I am trying to establishing some step by step to calculate the amount of energy is being absorbed by a water body when a LED pendant is shining right above. Being the parameter that I want to calculate, the energy absorbed by the...
  2. H

    Why am I blowing a laptop powerpack with dc water pump?

    Hi, I have a water pump rated 12v dc 2.3A. I tried using Microsoft Surface powerpack rated at 15v dc 2.5A to power it. Pump just started pulsing. I removed the water pump and checked the voltage coming out the powerpack and it was fluctuating between 0 and 15v. Thought I had a dud powerpack so...
  3. Strato Incendus

    Wall thickness of ring habitats for radiation shielding

    This is a topic that will be relevant for anyone who plans to use "realistic" artificial gravity (of the centrifugal kind, rather than the "acceleration-based" kind) in their stories - be it on spaceships or space stations: How much of the ring walls has to be dedicated to radiation shielding...
  4. MatinSAR

    Buoyant force acting on an inverted glass in water

    My answer : According to the question, the glass and the air inside it entered the water. Let's assume that the net force becomes zero at a moment, that is, the sum of the weight force and F is equal to the buoyancy force. By going down in the water, the gas volume decreases, so the buoyancy...
  5. A

    Does water electrolysis work efficiently under high pressure?

    One of the stages in hydrogen production after electrolysis is to run the hydrogen through a compressor and that can take a lot of energy. Would it be possible to run an electrolysis setup inside an already high pressure hydrogen tank so that the hydrogen being separated during the electrolysis...
  6. C

    Bernoulli’s Equation for plugging finger into dike under water

    For this part (b) of this problem , The solution is, However, why are they allowed to assume for the Bernoulli's equation for the water outside the hole, that the water is stationary (i.e v_1 = 0)? It also appears that they assume that the pressure inside the Holland is 1 atm, which is only...
  7. P

    Vapor pressure -- How does water still boil at 100°C in an open pot?

    Vapor pressure is the pressure of the vapor when it is in equilibrium with its liquid. This only happens when the container where the liquid is present is closed. Indeed, when the container is open, this liquid-vapour equilibrium is never reached, because the partial pressure of the vapor (at a...
  8. I

    Physics of Water in the Closed System of the Great Pyramid

    Hello, I am working on a theory for a Great Pyramid power plant and I need some help understanding if my current hypothesis is even possible and how to calculate how much water will fill the upper structure. I believe the water system to work as follows: An aqueduct delivers a steady flow of...
  9. epenguin

    B Disk with holes falling on water

    Just yesterday evening I saw a video of a few minutes where metal disks with holes in them were let fall into a basin of water.The water went up in twisted columns and made the most astounding and beautiful patterns. I thought I would show it to other people who might be interested - but I have...
  10. Z

    Strong Inequality Hydrodynamics: Flat Cylinder in Water

  11. P

    Energy/Power Question for pumping water out of a well

    Im guessing you start off with P=E/t but I'm unsure of what I need to sub in, in order to solve for v. P = 1000W h = 20m v=?
  12. mastermechanic

    I Vertical acceleration of the water bubbles in a kettle?

    Question is simple, as we all know water boils at the bottom surface and it forms tiny bubbles. These bubbles grow up and rise in the water until they detach. What is the acceleration of these bubbles compared to gravitational acceleration? - Is it constant velocity? - Is it approximately...
  13. A

    Reusing Isopropyl Alcohol bottle for Drinking Water?

    Hello, I’m an electronics hobbyist, and fairly regularly buy isopropyl alcohol for cleaning with that, and to clean a vaporiser as well. I recently found my electronics store started carrying 5 litre bottles. They are strong, and the screw top thread, in particular, is substantial, so I thought...
  14. D

    Dissolving Particles in Oil (but Water resistant)

    Hello Everybody, I have a superoleophobic surfaces which shows high contact angle for Water, Oil, Hexadecane... I am looking for a kind of particles which are attached to the surface and once I touch them with a droplet of oil are dissolving in that oil droplet. If I then remove the droplet...
  15. A

    Air wedge interference pattern after being filled with water

    An air wedge is illuminated with light and an interference pattern is produced. What will happen to the interference pattern when the air wedge is filled with water? The answer given at the back of the book is that the fringe spacing of the interference pattern will increase, however my...
  16. Induana

    B Hydrostatic pressure in a bottle of water on ISS

    Hello, I am new in physics but I really like it so far. I have a question about hydrostatic pressure. I know that hydrostatic pressure equals (height)x(density)x(g). Am I right if I say that hydrostatic pressure in a bottle of water on ISS (state of weightlessness) will be zero ? Thank you for...
  17. person123

    I Momentum of a Water Jet Impacting Plate

    Suppose you have a jet of fluid (say water) traveling vertically upward at a constant velocity. It impacts a stationary horizontal plate and so moves radially outward in all directions. Assume that there's no energy loss during the impact, so the speed of the fluid remains constant. Is momentum...
  18. S

    Hydrostatic pressure at a point inside a water tank that is accelerating

    I draw this diagram: The formula for hydrostatic pressure is: ##P=\rho g h## so I just plug everything $$P=1000 \times 9.8 \times 0.1=980 Pa$$ Will the acceleration of the cart affect the hydrostatic pressure? Another thing that came to my mind was there would be extra force coming from...
  19. Astronuc

    PSA - Shallow water drowning, aka shallow water blackout

    An unexpected result from a seemingly harmless activity - holding one's breath underwater. https://www.yahoo.com/news/watched-husband-almost-die-front-104525608.html An otherwise healthy 27-year old man held his breath underwater, then his heart stopped. It is surprising, since I used to do...
  20. M

    Calculating total heat transfer by solar water heater

    I have a solar water heater on my deck, with a circulator powered by PV, that pumps heated glycol through a wand heat exchanger placed in an 80 gallon tank. Water comes from the well's pressure tank, passes through this solar pre-heater tank, then into an LPG heater that adds any heat needed. I...
  21. gggnano

    Can I make a rocket by mixing aluminum + iodine (+ water catalyst)?

    Basically it's a well known reaction, many kids on youtube make it for the views: I am thinking, since AlI3 sublimes can it be put in say tungsten bottle (is this even a thing??) and then used as a rocket the same way Na+H2O or HCL+Al rockets are used - the gas escapes? This phase...
  22. S

    I Water powered funicular with equal masses?

    I found a paper (https://www.researchgate.net/publication/312123871_Introducing_a_Modified_Water_Powered_Funicular_Technology_and_its_Prospective_In_Nepal) where the authors design a funicular system powered by water but with a modification from traditional systems where apparently the funicular...
  23. N

    Fluid Dynamics Question -- Water flowing through a pipe into two cylinders

    Because my little work project involves fluids I thought this the best topic to post under. I took the route of biological sciences and computer science. This area is out of my league at the moment I'm not sure the amount of time that would be required to get the material applicable to this...
  24. Sphere

    B Why does increasing the height of a water tower increase water pressure?

    Hello, I was wondering, for a fixed amount of water, why when the height of a water tower increases, the water pressure at the outlet of the pipe at the base of the tower increases ? I have often read on the internet that it would be caused by the weight of the water above the water at the base...
  25. casparov

    I Physics of paper absorbing Water -- Doesn't this decrease Entropy?

    Summary: doesn't this decrease entropy ? Cellulose is known for its hydrophilic quality, which can be explained from the polarity of its hydroxyl groups. We all know water can overcome the force of gravity through a piece of paper you put in the water. Correct me if I'm wrong but this is a...
  26. tarakmytar

    I Water converted to plasma -- how does this work?

    In its path to the exit it is, disassociated, and still trapped in this enclosure with only a path forward. So now it is in two forms of gas, so the pressure of the expansion in the enclosed enclosure and now traveling at high speed towards the exit, and most likely ionized. It is then subjected...
  27. BlackPhysics

    A cylinder with cross-section area A floats with its long axis vertical

    Summary: A 5.0- cm -diameter cylinder floats in water. How much work must be done to push the cylinder 11 cm deeper into the water? F =Aρgx A 5.0- cm -diameter cylinder floats in water. How much work must be done to push the cylinder 11 cm deeper into the water? F =Aρgx x being the...
  28. unoonu

    Relative Velocity Against the Water Current

    vcanoe_wrt_ground = 3 m/s + (-6) m/s = 3 m/s - 6 m/s = -3 m/s Thus, if I understand this correctly, the rower will never reach his goal 36 m away as his canoe's resultant velocity is negative (i.e., his canoe is effectively going downstream even though it is trying to go upstream). My only...
  29. L

    How do I make water fizzy without carbonation?

    I have had seltzer water which is merely carbonated water which is more acidic hence a more sour flavor as shown in link below. Is there a non-toxic gas that can be added to water to give it bubbles that actually makes it more alkaline? And if so, perhaps combining it with carbonation so the PH...
  30. Frankenstein19

    Will dissolved oxygen increase in a water sample inside a jar?

    If I have 100mL inside a glass with a closed cap. I take the cap off, measure DO, put the cap back on and decrease the temperature 20 degrees. No agitation of any sort. Does the DO increase?
  31. Spiffyline153

    I Uncovering the Secrets of Water Slide Physics

    I'm a researcher hoping to look at some papers on the technical aspect of water physics on a water slide. Does anyone have resources or pointers for me? Essentially, I'm trying to find the optimal amount of water needed to propel a passenger down a standard straight water slide, but I don't know...
  32. T

    Is it worth it to buy distilled water?

    Hello, not sure whether this subject belongs in the chemistry or biology. A guy I met at a public place I got to sometimes during the week told me that drinking water or tap water from faucets in homes, espeashally very old homes isn't safe to drink or has toxic stuff in it that's not good for...
  33. P

    A Antiproton reactions with water

    This started out with interest on antiproton radiotherapy but as it turns out there's little to no publication on the reaction equations that's happening. So this is just an attempt to have some equations at hand. The reactions are for antiproton with water. For simplicity everything is...
  34. W

    I Why Doesn't the McLaren Oil in Water Engine Work?

    Here we have an oil engine. Oil is fed in at the bottom of a column of water, rises up and collects at the top of the column, it overflows into an adjacent column which could be of larger diameter, and is fed back into the column of water. I know it won't work but can someone please explain why not?
  35. kma

    I What happens to resistance of tap water as voltage is increased?

    1 In recent days I have done a few experiments measuring the current of water as it goes up from 9 volts up to 36 volts, and following Ohms law to convert it to resistance. And I discovered a very interesting trend. In between 9 and 18 volts, there is a massive drop in resistance (by around a...
  36. person123

    Where can I find a PVT table for water for a 3-D webapp?

    I'm looking to create a little webapp where the user can see the 3-D PVT phase diagram, giving the user functionality like orbiting the surface and moving a point along the surface. (I attached an image of the surface I'm referring to). To do that, though, I would need the data defining the PVT...
  37. wessholders

    I Water flowing through a funnel

    Will water flowing through a funnel be accelerated more by a "curve-walled" funnel rather than a "straight-walled" funnel?
  38. H

    How can I save gas when boiling water on my gas stove?

    Every morning I boil two eggs for ten minutes. My gas canister emptied faster than I thought it would. Now I had noticed that most of the air heated by the gas never touches the pot. I had another burner with half the diameter of the one I had been using. That means 1/4 the circumference...
  39. M

    I Water bath and water vapor + air mixture in a closed system

    Hello, At my work I came up with the following question: Say we have a vacuum chamber. Inside the vacuum chamber we have at the bottom a water bath. The rest of the chamber is filled with a air and water vapor mixture. The whole system is placed in a room, is at room temperature and is in...
  40. J

    Question regarding water pressure and slopes

    I have a question about water pressure PSI regarding the presents/lack of slopes. If two identical pressure sensors are set up on the ocean floor at the same depth. One being surrounded by a cone of ramps increasing in height moving outwards away from it. The second sitting on a flat plain...
  41. L

    A Will air turbulence in flexible airduct causes water condensation?

    In a normal aircond system using flexible airduct, assume airflow with temperature & humidity conditions (Tdry=23°C; Tdew=13.4°C; RH=55% ) go through a bended flexible airduct where air turbulence is formed: 1. Can condensation happens at the bended flexible airduct due to air turbulence? 2...
  42. J

    Water flow thru 18" corrugated culvert

    Attached formula can't figure out. H is 12 inches, Q is what I want to know, L is 40 feet, D is 18 inches, A I assume is area of 18 inches, g have no clue what this is. The Culver is 18" X 40 foot long coragated with water 1 foot over inlet and water on outlet 2" lower than culvert and the...
  43. M

    Upward force of float moving in an arch under water

    a float with 5 pounds of water displacement is resting on the bottom of a pool of water 10 feet deep. The float is tethered to the bottom of the pool via a string that is pulled tight lengthwise and so is also laying on the bottom of the pool. The string is 4 feet long. If the float is...
  44. camerart

    Maximizing Heat Storage in Water: Photovoltaic vs Radiator

    Hi, I'm going to make a comparison test between Photovoltaic solar panels and the radiator type. I intend to store all heat with an insulated water tank. Many years ago, I heard about water bottles in a green house with some kind of salts in the water, which allowed the water to store more...
  45. T

    Engineering project: Harvesting energy from natural water fall

    - design of a micro-turbine based on different scenarios of waterfalls - build a system that involves a battery for storing power - test in the lab I have attached a image. I know the image is not very detailed but wanting some advice on this situation. I have done some water calculations on...
  46. J

    I am grappling with a gravity fed water system and have questions

    How did you find PF?: Google I have an off grid home that uses a spring fed gravity flow water system. The spring is about 200 feet up a steep mountain- and very low flow. The pipe run starts at 2” pvc and eventually is 1.5” pvc. Once down the hill the water flows about 1 mile down an old...
  47. HelloCthulhu

    Mathematically expressing field driven water autoionization

    I recently read a paper on using an electric field to drive water autoionizaton. I'm trying to figure out how to use the Laplace equation on pg 9; 4th paragraph; to solve for voltage. I'm also interested in how this equation would change if I replaced the hemispherical tip with a parallel plate...
  48. PainterGuy

    Medical Drinking water and the release of gastric acid

    Hi, I think of a human body as an intelligent biological machine. Could you please help me with the query below? Question: The stomach produces gastric acid and pepsinogen among other enzymes etc. When a glass of water is taken without any food, wow would the stomach react to water? Assume...
  49. jaumzaum

    B Why is sea surface water relatively constant?

    I'm studying oceanography and the author of the book that I'm currently reading stated that sea surface water is relatively constant during the day, changing very slowly during the year. He says "this is because almost all the energy received from the sun is used in the evaporation of water"...
  50. ContrapuntoBrowniano

    B Ideal gas formula not working?

    Hi! I wanted to do some basic calculations for temperature T on a water-filled pot. I noticed something strange on my calculations, and couldn’t figure out what was wrong... So here it is: The ideal gas formula: k=PV The actual formula Relates equally the product PV with the a constant...
Back
Top