Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.
10
votes
4answers
5k views
Why does adding solutes to pure water lower the the specific heat?
We found that water with salt, sugar, or baking soda dissolved in it cools faster than pure water.
Water has a very high specific heat; how do these solutes lower it?
We heated a beaker (300ml) of ...
5
votes
1answer
936 views
Why is boiling water loud, then quiet?
Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was ...
10
votes
1answer
212 views
Could there be a body of water the size of a planet?
My friend and I were reading the news of the discovery of a black hole spewing huge amounts of water vapor into space, and it got us thinking: could there be a blob of liquid water in space the size ...
12
votes
4answers
2k views
Why are snowflakes symmetrical?
The title says it all. Why are snowflakes symmetrical in shape and not a mush of ice?
Is it a property of water freezing or what? Does anyone care to explain it to me? I'm intrigued by this and ...
8
votes
4answers
1k views
Are water waves (i.e. on the surface of the ocean) longitudinal or transverse?
I'm convinced that water waves for example:
are a combination of longitudinal and transverse. Any references or proofs of this or otherwise?
6
votes
2answers
146 views
Why water in the sink follow a curved path?
When you fill the sink with water and then allow the water to be drained, the water forms a vortex.. And then it starts to follow a curved path downwards by effects of gravity..
Why this phenomena ...
1
vote
3answers
553 views
Maxiumum weight a buoy can float [closed]
I have a buoy that can hold 2943.02 cubic millimeters of non-pressurized air, I need and equation to work out the maximum weight that the buoy can float.
23
votes
2answers
2k views
Before a once-warm lake starts to freeze, must its temperature be 4°C throughout at some point?
This is a problem I just started puzzling over, and I felt this would be a good forum to check my reasoning. So here are the relevant observations followed by my question:
Water achieves its maximum ...
10
votes
4answers
13k views
How does water evaporate if it doesn't boil?
When the sun is out after a rain, I can see what appears to be steam rising off a wooden bridge nearby. I'm pretty sure this is water turning into a gas.
However, I thought water had to reach 100 ...
6
votes
1answer
331 views
Microwave oven + water: dielectric heating or ion drag?
When you place a water or food in a microwave oven, it heats.
Which process commits more energy to that: dielectric heating, or ion drag i.e. resistive heating?
AFAIK, in distilled water (which is a ...
3
votes
2answers
794 views
How does the process of freezing water remove salt?
How does freezing water to make ice remove whatever salts were in the water to begin with?
6
votes
1answer
658 views
How fast would someone have to run to run over water?
I was thinking about Flash, the superhero, or the little boy in the Incredibles.
There is one Yahoo answer that doesn't answer a lot. Especially, I don't think surface tension would help a lot for a ...
8
votes
2answers
393 views
What is the status of Mpemba effect investigations?
There is this puzzling thing that is called Mpemba effect: paradoxically, warm (35°C) water freezes faster than cold (5°C) water. As a physisist, I've been asked about it several times already. And I ...
7
votes
1answer
738 views
water flow in a sink
When one turns on the tap in the kitchen, a circle is observable in the water flowing in the sink. The circle is the boundary between laminar and turbulent flow of the water (maybe this is the wrong ...
6
votes
3answers
2k views
Why does frozen water burst a pipe?
When water freezes in a pipe it can crack the pipe open. I assume this takes quite a lot of energy as when I try to crack a pipe it can be hard work!
I think water freezing is a result of energy ...
6
votes
5answers
2k views
Why does water make a sound when it is disturbed?
When I disturb a body of water, what causes the familiar "water moving" sound?
4
votes
3answers
1k views
Why does hot oil explode when pouring water on it?
I am puzzled to know, What is the reason of hot oil make sound and explode when we pouring water on it?
13
votes
1answer
241 views
Why is boiling water the second time more quiet than boiling it the first time?
First of all: This is a different question than Why is boiling water loud, then quiet?, although the answers might be similar.
When I wake up, I boil some water for a cup of tea. It happens quite ...
8
votes
5answers
336 views
What can wavy patterned sand tell about the Fluid that formed it?
Sand on the bottom of the ocean as well as sand on the low-tide beach often forms wavy patterns. Do the parameters of these wavy patterns have any relation to the water and waves that formed them? If ...
5
votes
3answers
493 views
Is a water world possible, and for how long could it be stable?
I have several questions regarding this topic.
First, could a water world be stable for thousands of years with most of its surface remaining covered in water. What would it take for this to be ...
4
votes
4answers
417 views
How far can water rise above the edge of a glass?
When you fill a glass with water, water forms a concave meniscus with constant contact angle $\theta$ (typically $\theta=20^\circ$ for tap water):
Once you reach the top of the glass, the water-air ...
4
votes
2answers
2k views
Flow of liquid among branches
If water is flowing through big pipe is branched into 4 branches of small pipe. Lets say the flow is around 4 m/sec.
I have the following questions:
What will be the flow rate in each of the ...
3
votes
3answers
238 views
How can my water cool down more quickly?
I have a cup and I can only pour hot water inside, I wanna know whether the heat will dissipate more quickly with more water or less water?
How about the occasion when my cup is well covered?
2
votes
1answer
408 views
How much water must flow trough canal to maintain a constant water deep?
In order to maintain a constant water deep in canal, how much water must flow trought the pipe ?
As shown on picture, canal have a rectangular shape.
I don't know if canal length have an influence.
...
2
votes
1answer
258 views
At what temperature does water become a liquid on Mars? On the asteroids? And in a vacuum?
I know that I can just read off the phase diagram for water (for the surface atmospheric pressure on each object). But could there possibly be some nuances that someone might miss just from viewing ...
2
votes
1answer
220 views
Why does blowing on someone who is wet feel colder than on someone who is dry?
The title says it all. If I'm standing in the wind and I'm wet, I feel much
colder than when I'm dry. This is true no matter how warm or cold the water.
Why is this?
1
vote
1answer
259 views
Does the Relative density of water change based on the state it is in
Will Relative density of water change based on the state it is in? Ie solid, liquid, gas.
What causes this change(if any) in Rd?
1
vote
1answer
139 views
Calculating temperature of water in the freezer
Assuming water volume ($V$), initial water temperature ($T_0$) and environment temperature ($T_e$) are known, what is the easiest way to calculate temperature of water in given time ($T$)?
For the ...
0
votes
1answer
1k views
Is sea water more conductive than pure water because “electrical current is transported by the ions in solution”?
Apparently, electrical charge is transported by the ions dissolved in water, is this true?
