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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40 views

I need to remove water from a system [closed]

I work in an industry and I need to remove water from a system. The scenario: There is a washer and a blower on a conveyor belt. The item being washed is plastic (not sure what type) and can't be ...
0
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0answers
38 views

How can we describe or model the spread of ice during the freezing of the surface of a still lake?

Premise: I live in a place where it is unquestionably wintertime in every aspect of the phrase. I was driving down the street and I drove by a lake. There was a recent and sudden temperature drop ...
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0answers
18 views

Heating water with low and high gas heat

Similar type question is asked before but i'm looking for other aspect of it. I observed that if water is heated with low gas heat, it takes long time but it retains it high temperature for long time ...
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2answers
577 views

What air pressure is needed on mars, to have fluid water?

The atmospheric pressure on the Martian surface averages 600 pascals (0.087 psi), about 0.6% of Earth's mean sea level pressure. There is a lot of frozen ice on mars, but it can't melt, because of ...
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0answers
35 views

How much does grabbing a piece of a plane free falling change your survivial?

Just for context let's saying you are falling from a plane in free fall position at 56m/s(200 km/h or 120 mph) and you grab onto a wing which slows you down to 25m/s. You weigh 70kg. so ...
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2answers
158 views

Where would a perfect sphere break under pressure?

My roommate who studies physics once showed me the leftovers of an interesting experiment: They filled up those metal balls with water and then froze it. The water expanded and with all of its ...
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1answer
30 views

Would it actually be possible to preserve a snow flake?

In episode one of season 3 of The Big Bang Theory Leonard offers Penny as a gift a snow flake he says he preserved in some kind of resin, having it brought from the North Pole. Is this purely ...
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2answers
1k views

When a drop of water falls into water, where do the splashes come from?

When a drop of water falls into a reservoir of water from a high enough altitude, water droplets will splash (image credit): My question: Does the water in those droplets come from the original ...
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0answers
33 views

Bond Angle in a water molecule

I recently started up reaching up on the Feynman lectures on Physics and in Vol I,Chap 1-2,Feynman states that the bond angle between the hydrogen and oxygen atom is 105° 3′. I know that the bond ...
3
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3answers
107 views

Why do square shaped cups spill easier than round cups?

I've noticed that when I use a cup that is square shaped with convex sides, it spills more easily than a circular cup. Why does this happen? What is the most spill-prone cup shape? What is the most ...
4
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3answers
229 views

Why does a pitcher with lemon juice have foam, while one with pure water does not?

Whenever I pour water into lemon juice (pouring directly from the tap into the pitcher, not quietly along its edge) I get a foam on top: The same pitcher with water (same water tap, pitcher, time ...
4
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2answers
74 views

Water level of ice in cup [duplicate]

Since ice is less dense than water, it floats on it, we all know this. Now suppose, if ice is floating in a glass cup, when the ice melts there should be some change at water level in the glass cup. ...
6
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3answers
196 views

Why is concrete dry around cracks?

On a warm and partly cloudy day this summer, I was sitting in my office and suddenly heard rain on the roof. I went outside to shut my car windows. By the time I did that and was walking back into ...
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0answers
134 views

How can I bring water to 90 degrees C? [closed]

For my coffee I need the water to be 90 degrees Celsuis. Boiling water, however, is 100 degrees. How can I make it 90 degrees? Do I just measure the temperature of the water from my tap, and if it's ...
1
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1answer
43 views

How do you work out the energy requirement for a submerged pump?

I was wondering if you were to place a pump in a submerged container and then were to open a hatch allowing water to flood the previously vacant cavity how much energy would be required to discharge ...
1
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0answers
20 views

Will Ice Cubes Form Quicker when Made from Hot Water or Cold Water? [duplicate]

When you put water in the freezer you can make Ice Cubes. But does the time taken for these Ice Cubes to form decrease or increase when the water which is used is hotter or colder?
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2answers
151 views

Why does room temperature water and metal feel almost as cool as each other?

From what I've read about heat, temperature and conductivity, I understand that the reason water at room temperature feels colder than most other things at the same temperature (like wood, air, ...
0
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2answers
70 views

Why are ripples formed in water round? [duplicate]

Despite whatever be the shape of object that you drop in water, it be 1D, 2D, 3D, they all produce ripples in a circular pattern, is this pattern followed under water as well (in terms of density ...
0
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1answer
79 views

What Is the Physics principle behind dropping a stone into a cup of water?

I have been doing an experiment about relationship between drop height of a stone and the loss of water in the cup it lands in. I found that after dropping the same stone into a cup with the same ...
1
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2answers
87 views

Why Does Air Hold More Water When the Air is Warmer?

I know that when the temperature of the air rises, the maximum amount of Water it can hold before the water condenses to water droplets increases. But why is this - has it got something to do with ...
6
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0answers
67 views

Why is the splash of water always vertical, no matter in which angle the gunfire hits the surface

When gunfire hits the surface of a pond, the water seems to always splash directly upwards, in 90° to the surface of the water, no matter at which angle the gun is fired. The angle is usually very ...
5
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1answer
62 views

How does the movement of molecules change at the edge of a liquid?

I am thinking about how the velocity of molecules measured from a small region of space might change as the region of inquiry moves closer to the edge of a container. Ultimately I am thinking about MR ...
5
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1answer
84 views

Superhydrophobic coating and water friction

If you were to apply super-hydrophobic coating to the hull of ships or even submarines, would you get more or less water friction? If the coating completely repels the water you could argue there ...
4
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3answers
74 views

Why does the light reflecting off of ocean water sometimes appear 'smoother'?

Looking out the window at some water in the Harbour - I noticed that some parts of the water appear 'smoother' than others. My question is: Why does the light reflecting off of ocean water ...
2
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2answers
133 views

What would a graph of temperature increase of a cup of water in a microwave look like?

My lunch had been in the microwave for a minute or so, and I was wondering if I took it out 10 seconds early, would the amount of temperature it increased in that 10 seconds be more significant, less ...
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4answers
61 views

Is it true that water go down the drain counterclockwise in the northern hemisphere and clockwise in the southern [duplicate]

Many websites say that water drain in different directions in Northern, Southern hemispheres. Some people say that Coriolis effect causes it. Some people say that it's not true.
2
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1answer
63 views

Water behaviour under theoretical near-infinite pressure conditions

I've asked a similar question here but the answer given shows the behaviour of water under general conditions. I'd like to know what the behaviour of water is like as pressures increase towards ...
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1answer
25 views

What concepts/rules apply for multi-stage pumping of water

For single stage (ie one pump) water transfers calculations for pressure loss are commonly done by adding the elevation difference of the start and end of the pipe line to the friction losses that ...
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2answers
30 views

why only surface of water get frozen in polar countries?

why only surface of water get frozen in polar countries? but if i kept glass full of water in fridge then not only surface, whole water turns frozen ,why?
0
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2answers
107 views

Why does freshwater attenuate signals less than seawater?

One of the most interesting problem in underwater communication is how deep the device (i.e. submarine) could go to still be able to communicate with on-shore data centers. The attenuation in a ...
4
votes
1answer
81 views

What is the effect of water 'climbing' over a cup via a wet string? [duplicate]

I have noticed (with tea bags, etc) that if you get the whole string wet, and you have one end inside the cup and the other end below the level of the liquid (outside), the water drains down the ...
2
votes
1answer
142 views

How to calculate the volume of water in a certain amount of air, given the relative humidity?

If, according to the weather forecast, the current humidity is 90%, how can I calculate the volume of water that could be extracted from a certain volume of that air?
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1answer
61 views

Does water diffuse trough rubber of car tire of when liquid or only as gas

Does Water difuse trough rubber of car tire when its liquid or only when its a gas. Can also be that is diffuses but slower when liqiud. I want to know this for my argumentation that filling car tire ...
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4answers
4k views

Why does water rise through a hole in ice

I've just been watching a doco where some guys cut a hole in a frozen lake, the ice is 3 feet thick, I was surprised that the water rose to the level of the ice. My friend assures me it's because ...
2
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0answers
75 views

Heat Transfer, Water in a pot

I have a question I've been pondering for a while. How can I determine the temperature in a pot filled with water? I know these things: I have a known mass of water, of mass $m_w$ I have a pot of ...
12
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1answer
113 views

Why does water appear still near the shore

Often when there's a light wind I notice this behaviour on lakes that there appears to be a very distinct line between the water with waves and the calm water. I don't know how well it comes through ...
3
votes
1answer
107 views

What is the maximum height for a puddle of water, assuming stp?

I wonder if anyone has figured this out. Assuming, standard temperature and pressure(273 K and 1atm), what is the maximum height of a water puddle on a flat surface? There might be some other factors ...
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vote
3answers
178 views

Why do cold drinks get sweaty?

I drink a lot of iced tea and live in a very humid part of the country. My drink accumulates so much water, I had to purchase coasters to collect all the water dripping from the sides. Where does ...
1
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1answer
312 views

Calculate Compressibility of water [closed]

I have 1 litre of water on 30 celsius, and there is a pressure of 10 mega psi affects on it. I want to calculate volume decrease that caused by pressure Thanks
-1
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1answer
1k views

What happens when ice melts? [closed]

Case 1: You take x litres of water and cool it to solid ice(say 0 degree) and measure the volume of ice as ...
1
vote
2answers
68 views

How much entropy is produced in evaporating water due to irreversible evaporation towards equilibrium (humidity=100%)?

$dS=dH/T_{boil}$ for the increase in entropy by changing a phase at saturation ($T=373\text K$ for $p=1\text {atm}$ for water). However, water also obviously evaporates below boiling point when ...
1
vote
3answers
45 views

Is a flow of ionized water an electric current?

If $H_2O$ ions have a net electric charge and electric current is the flow of electric charge, can a stream of water ions be considered an electric current? If so, is it conceivably possible (not ...
0
votes
0answers
30 views

Strange Spurting of Water

Yesterday, I punctured the base of a partially drunken 50cl bottle of Badoit sparkling water with a compass (the one used for geometry). For someone reason, a stream of water started spurting out of ...
21
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2answers
2k views

Why does a dish cloth absorb liquid better when it is damp?

Take a really dry dish cloth and try to wipe up some liquid you spilled on the kitchen counter. I will take up only so much of the liquid. Then try it with a damp cloth (or a wring out a wet one). It ...
2
votes
0answers
112 views

Calculating PSI generated by water entraining air as it flows down a pipe

This is the concept used in a trompe. Basically, the idea is that if we allow water to flow down a pipe and if that pipe has inclined air intake orifices near the top where the water enters, then the ...
0
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0answers
31 views

Sound vibrations for marine propulsion

I asked a similar question about bubbles making less friction on a mass moving through water, now I'm wondering of sound waves could do the same thing as supercavitation or possibly create it's own ...
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1answer
30 views

How big are soluted salts in drinking water?

I have just seen the TED talk Michael Pritchard: How to make filthy water drinkable where a device called LifeSaver bottle that filters particles that are bigger than 15nm out of water. I have heard ...
3
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2answers
109 views

How can water be liquid and gas in the same environment?

Think about it. If there's water in a gaseous form, how can there also be water in a liquid form? The gaseous water would have to have more energy than the liquid, but if it's the same temperature, ...
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3answers
120 views

What could be added to tap water to reduce air bubble formation on a submerged object?

Submerge your hand in a bucket of water. Some air bubbles appear immediately and others add to the surface of the hand over time. Is there anything that could be added to the water to reduce the ...
3
votes
1answer
77 views

What would happen if one drank only D2O for a long time? [closed]

Would it be lethal ? Would you gain 10% of your body weigth ?