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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54 views

Entropy changes of water

I have a few questions regarding entropy and water. Suppose you cool down water so that it freezes at $273.15K$. How is entropy positive in this case? I have a feeling it may have to do with the ...
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1answer
29 views

Can there be net condensation into a pool of water?

I'm curious about the equilibrium of evaporation and condensation. Given that the surface area of a dehumidifier's evaporation coil at 4C is proportional to the rate of condensation, how would the ...
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1answer
73 views

Time to decrease water temperature by 5F from different initial temperatures

Is the time to (naturally) decrease temperature of water by 5 degrees the same, regardless of the initial temperature? Imagine 3 glasses of water (a, b c) in a room temperature of 70F. There are 3 ...
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0answers
33 views

What are the physics principles behind “amphibious” camera lens windows?

Underwater camera housings have a window through which the lens looks. When the camera surfaces, a couple of things can happen, and I've seen both captured in the camera footage. In one case, water ...
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0answers
28 views

What do water stains make things appear dark? [duplicate]

If a piece of grey tarmac is damp after the rain, it appears darker. If I spill water on my carpet, the damp patch is darker than the rest of the carpet. Generally speaking, a lot of things appear ...
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1answer
133 views

How does a water-steam mixture behave?

Namely, if I mix a flow of steam that has density $\rho_s$, velocity $v_s$, and pressure $P_s$ with a flow of water that has pressure $P_w$, velocity $v_w$, and density $\rho_w$, how can I find the ...
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3answers
29 views

Breathe Air from a source without any pressure compensation?

I just thought about what I'd do if I was on a sinking ship and of course breathing was the first thing that came into my consideration. Now imagine the ship's front going up and the room you are in ...
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1answer
975 views

Why does surface tension of water-ethanol binary mixture decrease with increasing concentration of ethanol?

I was thinking that it must be due to weaker hydrogen bonding in ethanol than in water. But then I learnt that Raman Spectroscopy and viscosity measurements suggest that upto a certain ethanol ...
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0answers
43 views

How long does it take for disturbed water to stop making sound?

Suppose I have a bowl with water or another liquid. The water from the bowl is perfectly quiet. Then I throw a stone in the water and I wait. How can I calculate the time after which the water is ...
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0answers
77 views

Does the density of water ice (any form of water ice) near 0K exceed the density of water at 277.15K?

In a question brought up by my chemistry class, the most we have determined is that the stability of most forms of ice decreases as the temperature decreases. What does this loss of stability do to ...
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0answers
48 views

What will be the affect of Global Warming if Polar Ice melts? [duplicate]

Due to global warming, all the polar ice melts & sea level increases, with increase in humidity. Angular momentum of ice at pole is, very low. Due to shift of water, from pole to equator, it's ...
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2answers
97 views

Electrolysis boat engine

Would it be possible to create a submersible boat engine using the combined principles of electrolysis of water, ramjet propulsion, and hydrogen-oxygen combustion similar to that used in rocket ...
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0answers
65 views

Where are real limits of evaporative cooling?

There are many projects focused on utilising evaporative cooling for food preservation or computer cooling purposes. I have other thing in mind, however and that's cooling beer. Once you're outside, ...
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1answer
64 views

can ice crystals be molded into a structural shape in space

I know that water exposed to vacuum space first boils and then turn into vapor (sublimates) . Is it possible re use this vapor say inside a pressurized membrane, to mold it into a solid ice structure, ...
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0answers
62 views

What will be the final temperature of water when heating at a a rate 10J/s?

If I supply heat of rate 10W to water of mass 250g and initial temperature of water is 29 degC then what will be the final temperature of water when steady state is reached. **Water is heating in open ...
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0answers
37 views

Water as heat source in a heat pump

Consider we have water flowing in a pipe, which is working as a hot source for a heat pump. We are able to know the temperature of the water in both ends of the pipe, yet we don't have information ...
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1answer
47 views

High pitched noise as hot object hits water?

https://www.youtube.com/watch?v=9qSEfcIfYbw Just wondering what this phenomenon was called, and its cause? Would have googled, but I don't even know what it's called.
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22 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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0answers
38 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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1answer
178 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 ...
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2answers
58 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?
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0answers
42 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 ...
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0answers
62 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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0answers
68 views

How big could a bubble of air and water be in zero gravity? Assume air surrounds and fills a bubble of water

I am designing an all water planetoid for a new science fiction novel I am writing. The Planetoid is a spherical bubble of water filled with air, and covered by a sufficiently thick atmosphere to ...
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3answers
718 views

Why are some surfaces slippery?

Why are ice and oil slippery? In general, why do certain substances make a surface difficult to walk on?
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0answers
135 views

Solar still and how it works

I use a solar still that holds 182 cubic feet of water. Here is how it works: There is an insulator on both sides of the metal bowl. On the outside it covers the whole thing. on the inside it covers ...
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1answer
93 views

Exception to weight of hot vs cold water?

I have seen the various posts regarding the comparison of weight of heated and cold water.But is there any contradiction?I live in really hot conditions and as such tap water literally 'boils' ...
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0answers
20 views

Water Displacement in the Oceans As a result of Global Warming [duplicate]

Not sure if this is the right place to ask this but here goes. If the north pole ice sheets melt, everyone agrees this would be a bad thing, however one of the reasons they state for this being a bad ...
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0answers
47 views

How come evaporation is possible? [duplicate]

If I have wet clothes and put them on the ground and let the Sun shine on them, they dry as water evaporates. But water should evaporate at 100 degrees Celsius so how come they go dry if it's just ...
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0answers
62 views

Optimal temperature for Mpemba Effect

Is there an pptimal temperature for the Mpemba Effect? Is there an optimal initial water temperature for speedy freezing? If so, what is it? If a specific example is needed: There is a 100 milliliter ...
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0answers
347 views

when water falls to the ground and forms a puddle, where does most of the energy go?

When water falls from some height to the ground and forms a puddle, where does most of the initial potential energy go? Sound, heat, surface tension, or motion of the earth?
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0answers
66 views

Is it possible for a planet to be made entirely of water (even it's core)? [duplicate]

I was thinking about this today... Is it possible for a planet to be made almost entirely of water (H20)? I'm sure that other elements would be in the mix, but I mean almost entirely made of water. ...
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3answers
1k views

Pascal's law: pressure of fluid at different locations

I know that's stupid question, but I'm really confused what my teachers says, so I need to check that theory. Here are just two ordinary connected containers, which are full of water. On grounds ...
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1answer
56 views

Depends river stream on river level?

If we have referral particle in the middle of the river, will it's velocity increase with higher river level?
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2answers
593 views

What is the ion drag mechanism in dielectric heating?

While reading about dielectric heating on Wikipedia, I read about the ion drag mechanism but there wasn't enough information about. I know there is another Phys.SE question talking about the ion drag ...
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0answers
416 views

Reduction in velocity in pipe

I have two pipes divided from main pipe. If I add one more pipe, what would be the amount of velocity in each pipes. I know the velocity of main pipe, then diameter and radius of each pipe. Edit: 1) ...
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2answers
1k views

How much water from ice and after how much time? [closed]

I need two formulas in dealing with ice and water. First: If I have 2 x 2 x 2 (cm) ice cube, after it melts, how much water will there be ? Second: If I have 2 x 2 x 2 (cm) ice cube, after how ...
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1answer
188 views

Water and steam ratio

What is the relationship between the water and steam? I've read that 1 mililiter of water evaporate to 1.6 LITER of steam. Is that true?
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3answers
82 views

Velocity of water from a certain depth

I was curious to know does water come out of a certain depth when there is a difference in pressure, and also if it does come out of a certain depth, at what velocity does it travel at? So, ...
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1answer
48 views

The physics of a drying shirt

So, I've noticed this enough times to state my observations. I wash some shirts and hang them up to dry. Sometimes I need to wear one before they have completely dried. What I have noticed on ...
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1answer
7k 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
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2answers
346 views

If a planet were cut in half but stayed hemispherical, how hot would the ocean on the flat side be? [closed]

Some time ago I asked a question about gravity on a hemispherical planet. What would gravity be like on a hemispherical planet? Would the water all boil away at first, quickly cooling the core of ...
-1
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1answer
844 views

Percentage of water that is void or empty space?

At the atomic level, at sea level on earth, what percentage of normal pure drinking water is void or empty space? What percentage of lead (the kind used to insulate from nuclear radiation) is void or ...
-1
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2answers
225 views

Torricelli's speed of efflux law

Torricelli's law states that if we make a hole in a container of fluid open to atmosphere, then the speed of the fluid spouting out is: $$\sqrt{2gh}$$ Does this velocity correspond to the horizontal ...
-1
votes
1answer
995 views

What happens if we put a pinch of salt on the ice cubes which is melting in the water?

What happens if we put a pinch of salt on the ice cubes which is melting in the water? How will the ice react to the salt, and what other things will happen after mixing them?
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1answer
158 views

What is the physics concept in sponge filter

I really need help I want to ask what is the physics concept in Sponge Filter?
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1answer
747 views

Time constant of ice melt

I'm familiar with problems of "how much ice can you melt given some amount of energy", but I'm writing to get some clarification on the time constant of this event. This question might be somewhat ...
-1
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0answers
21 views

Is the change in viscocity of water at 1C vs 99C discernable visually?

Waters viscosity varies from 1.7 at 0C to .3 at 100C. Is this visually confirmable?
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1answer
92 views

Boiling water function

i want to make a program that realistically boils water with all the variables but know near nothing about the math i got the energy transfer equation down but this seems to be giving me some ...
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2answers
451 views

How long will it take to fill a bath tub with oil compared to water?

As everyone knows, the oil is more viscous than water. But, I've been wondering how long it will take to fill a bath tub compared to water. It is quite obvious that oil will take longer. But, how much ...