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.
I mention the details in the book (verbatim) in the form of a paragraph in green below. Later I ask my questions in blue font for better reading.
"Surface tension also explains why hot, soapy water is used for washing. To wash clothing thoroughly, water must be forced through the tiny spaces...
So in a DnD story, someone made a bomb by putting 3375ft^3 of water into a 0.5ft radius sphere and caused it to make a nuke. I was thinking if this was possible then what would actually happen, so I spent an afternoon looking for the answer and only got the pressure and density...
I am trying to understand the science of stone skipping.
First, if the stone is thrown vertically would it bounce at least once for any possible velocity or does it go down only?
What sort of collision is it when the stone touches the water and how to look at conservation of momentum in this...
Suppose I have a perfectly circular pool which is four meters in radius, two meters in depth, and filled with water. Say I drop a steel ball with a radius of five centimeters into the middle of the pool from a height of five meters above the water's surface. After three seconds, what will be the...
I am in the process of designing a pumping/piping system for fun, have no experience in this field, but I enjoy learning. I have been using ANSI/ASME codes in the project quite a bit.
For the system I am using 4" nom. Schedule 40 316 SS pipe. The reason I selected the pipe is because the...
I have the solution for this problem but I did not understand the following statement:
The mass of water the crown displaced is ##m = 740- 690= 50 g##. Therefore the volume of the crown is ## 50 cm^3##
how can I conclude the volume of the crown from that displacement?
I was looking for on the internet for a while without a success.
If I know that the surface tension of pure oil is ##\gamma_o=A## and I know that the surface tension of pure water is ##\gamma_w=B##
so if I have a mixture of water and oil with surface tension ##\gamma_m=C## am I able to know...
From This picture, I think the fish will be smaller but the problem is how small will it be?
(Fish "L" is the image of fish "K")
Let ##H## be the depth of fish "K", ##\theta## be the angle of eyes to y-axis and ##n## is the index of refraction of water.
Vf = ?
y = ?
ME = mgy + 1/2mv^2
ME = 56*9.81*y + 1/2*56*1^2
Ui + Ki = Ui + Ki
gyi + 1/2vi^2 = gyf + 1/2 vf^2gyf = 1/2vf^2
vf = 5.425 m/s
9.81y + 1/2*1^2 = 9.81*1.5 + 1/2*5.425^2
y = 2.949 m
MEi = 56*9.81*2.949 + 1/2*56*1^2
MEi = 1648 J
The picture for this problem really confuses me. I am...
tank with water is pushed from construction into freefall,
A is at 0.1m depth
B is at 10m depth (so manometer will show aprox 1bar of hydrostartic pressure when tank is at rest on construction)
from 0-5sec tank is accelrating,after 5sec tank is falling with constant speed..1)is hydrostatic...
So I have made force diagram
And I think that I should find the acceleration by using these equations:
##\sum Fx=w\sin(15)-f_k-T_{x-buoyancy} ##
##\sum F_y=N+T_{y-buouancy}-w ##
I know that the volume of water displaced must be ##V=\frac{1}{2400}m^3## and the mass of the water is then...
I need to calculate how much liquid (mass) could cause a relative humidity of 10% in a pipeline. The pressure in the pipeline is 38 barg and the temperature is 105 °C. I calculated the partial pressure of the water which would be 3,74 bar (with formula relative humidity and antoine...
Is there some property that I can look up which would tell me how much water a hygroscopic salt can absorb (per unit mass of salt; for example anhydrous lithium chloride) before it's saturated and won't absorb any more?
Hello everyone, in one of my projects I am dealing with the following problem:
We have a tank filled of water. If we assumed that a focused ultrasond beam hit the water perpendicularly to the surface. How
can I calculate the displacement of the water surface? In particular, I am interested in...
Why can a shock wave condensate water droplets in the air and produce the visible vapor cone that we see when objects move faster than the speed of sound. Also, does this condensation happens only when the object is moving with a velocity greater than sound velocity? I don't understand the...
Hi PF!
Suppose I have a square tank of water. If I drive the tank of water such that it's height as a function of time is ##h(t) = \cos(t)##, ignoring gravity, is this the same thing as saying the tank is holding still but the pressure field is changing as ##p(t)=\cos(t)##?
I've been interested in the effects of electric fields on water for a while and came across this impressive demonstration of the water bridge experiment:
The thing that fascinates me the most is how much the electricity arcs out of the water. For example at timestamp 8:43 the arc clearly goes...
It's a decanter that we used for some wine a week ago. After rinsing it out and letting it drain I set it upright in the window box so that it could dry. The sun hits it every day. It's been a week and still the condensation is there. It's got a narrow opening, sure, but still... shouldn't it...
A thermal flask with water of temperature 90c is placed out in room temperature 20c, sealed. How long before it reaches 55c?
outer radius and height: 5cm, 25cm
volume of water is 1litre.
R = 0.5 Km2/W
using this equation to solve it combining these two and integrating with respect to T...
Hello everyone,
I am very interested in knowing the relation to determine the pressure required to push the water upstream.
In the attached picture, water is filled inside a tank of volume V and air is constantly flowing inside the tank through an inlet with constant flow rate M. Water should...
Let’s say we have a boat whose longitudinal axis is the y-axis (which goes into the screen in the figure below) standing upright in a still water .
##S## is the Center of Mass of the boat and ##C## is the Center of Mass of the displaced water.On ##S## lies the force ##\mathbf W##...
I have two more questions:-
(1) Can we calculate the time it takes specifically for water to radiate all its heat?
(2) Heat is illustrated as kinetic energy of molecules, so why collision between particles should result in the conversion of kinetic energy into radiation. Why conservation of...
First, I calculated the heat required for the ice to melt:
Q=mLf
Q=0.150×330
Q=49.5 J
Then, I calculated the final temperature of the water by forming the following equation:
Q=mcΔT
−49.5=(0.15+0.35)×4200×(Tf −80)
Tf=80.0 degrees Celcius
But the answer says 32 degrees Celsius.
Equal masses of ice at –10ºC and water at 80ºC are placed in an insulated container and allowed to reach thermal equilibrium. Calculate the equilibrium temperature
Data:
Water(ice): 37,65 J/mol.K Agua (l): 75,29 J/mol.K
## Lf = 6011 J/mol ##
I solved it this way:
## -Q_{l} = Q_{ice} ##
##...
If I was required to select a water pump for either domestic use or industrial, what are the consideration that I should take care of while choosing?
How can I select a suitable pump according to height? What power should be implemented?
Anyway, a general question would be "What is a reference...
Suppose you have a cylindrical column filled with packed, irregularly shaped particles. The bottom of the cylinder is flat and closed except for an array of small circular holes, regularly spaced except for a ring around the edge of the bottom where there are no holes. So, holes everywhere on...
I have an odd question; do you think that bleach water, rubbing alcohol, or quaternary can get into microscopic pores in plastic? About 10 microns or less in size?
Or is bleach water and others i listed to big of particles?
Thanks
This is the question: You want to make an electric instantaneous water heater in which 5.0 liters of water flows past a resistance per minute and heats water from 10.0 ° C to 45.0 ° C. Calculate the magnitude of the resistance to use and the amperage. The flow-through is connected to 230V
So...
I assumed p(r,t) as p(r,t) = R(r)T(t) as Separation of Variables method. I got the expression of T(t) as
T(t) = C1eC2t
and got a non-linear differential equation in R(r) as
d2R/dr2 + (2/r)dR/dr - (C/D)R = 0
(I assumed r to be the radial distance in spherical coordinates)
Now I'm not getting...
(The picture below is my drawing. I followed the instructions of the problems and drew for reasons of clarity.)
Let me start by writing down the given details : Volume of drum ##V_D = 0.05 m^3##, mass of drum ##m_D = 5 kg##, height of water column (initially) ##h_W = 1 m##, base area of water...
So, I was studying about general properties of matter and topics like surface tension. I came across the phenomenon of water rising along a glass plate like in the picture. I looked for some mathematical interpretation of this on the internet and in some books.
[![enter image description...
How would I calculate the damage anything would take if a human were to pick up water and throw it? I would like to know this for a game idea I'm coming up with. I researched a bit online about certain physics that could apply (I.E: classical, modern, classical mechanical). I'm just not 100%...
Hello, thank you for your attention in my thread.
I'm the head of Youth Science Club on one of the many High School in Indonesia, I got many members and I want to guide them for doing water sampling and analysis. In the history of my high school, no one is able to do water sampling and...
I'm asking the question because I'm interested in learning more about how ionic compounds behave in and around electric fields. I'm not actually going to make the proposed electret. The color of the Jello is irrelevant, and Jello may not yield an everlasting electrect, so it's more about the...
Building visibiity sensor...
What is best angle to detect water vapor reflection from laser, and refraction?
I plan to have two open cylindrical containers painted flat black and put inside each other so the overlap is about 0.5-1" (adj to limit ambient light vs airflow).
Laser is cheap red...
Would you able to tell me what’s the ideal angle Of a curved glass in order to Magnify an object inside an aquarium to the maximum. Also what would be the ideal distance of the object inside the aquarium. Sorry if I didn’t explain myself properly. I‘m hopeful somebody would be able to explain it...
Hello everyone,
I'm just doing a bit of review of math to be used in electrolysis calculations. From the reference:
https://www.ccmr.cornell.edu/wp-content/uploads/sites/2/2015/11/Saucedo_Skyler_splitting-water-with-electricity.pdf
the result for r12 on page 4, the author has 1.5 * 10e-11 m...
Hello,
I have built a device and i want to test different types of nozzles. Problem is; the size of the nozzles i need are hard to find in company stock. So i need to make sure before i make any order.
I have no background or degree any related area so it is hard to understand the equations...
the entropy change for a reversible adiabatic process is zero as it remains constant. Is this a reversible process?
assuming T1>T2:
hot (h) water has mass M, temp T1
cold (c) water has mass nM, temp T2
let the final temperature be Tf
if δQ=0 as the process is adiabatic, |Qh|=|Qc| so Qh=-Qc...
Suppose we have a copper wire, of resistance R, and we introduce it in water, when applying now a certain potential difference between the two ends, will the intensity that circulates through the wire be the same, and therefore also the resistance ?, is there going to be a potential drop due to...
Homework Statement:: Simualte the behaviour of water around an mhd inductive thruster
Relevant Equations:: https://www.comsol.fr/paper/download/45837/Pintus.pdf
Where can I start this simulation ? What is the required software ?
[Mentor Note -- thread moved from the technical forums]
Recently I viewed the Searaser video at
After watching it, I feel the numbers given in the video could be wrong but not sure. So I'd like to know how I can calculate the amount of water pushed by the Searaser device at some height in one wave shot e.g. at 100 ft, 200 ft and 300 ft above sea...
I assume the water to start flowing from rest at position 1, hence ##v_1 = 0##. Applying the continuity equation, ##A_1 v_1 = A_2 v_2##, we find the (wrong) result that the velocity at position 2 is ##v_2 = 0## also! (We assume that ##A_2## is small but finite)
Hence, to answer the question...