Two Hydrogen atoms covalently bonded to one Oxygen atom. One of the more common compounds on the surface of the earth.
4
votes
1answer
164 views
Can you measure the speed of water coming out of a hose by its arc?
Water comes out of a horizontally stationed hose and creates an arc as it heads towards the ground. Can I determine the speed the water was traveling in when it exited the hose by the measuring the ...
1
vote
1answer
217 views
Pump pressure required to fill water tower
I have a water pump at a distance of x meters from a water tower located h meters above the pump through a pipe with diameter d. I am not concerned with the exact value just want to make sure my pump ...
0
votes
2answers
138 views
Why laundry dry up also in cold/frost?
Why laundry dry up also in cold/frost? When you have frost, water in the clothes should freeze, but if clothes are dry, then it should be possible that steam in the clothes does not have time to ...
1
vote
0answers
53 views
Determining Water Level
Given a cylinder of a constant shape and size, how can the water level be calculated using the inside surface of the container?
For instance, could the inside lining of the container be a pressure ...
4
votes
4answers
429 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 ...
2
votes
1answer
74 views
DIfference in Pitch Caused by Water Temperature?
I have recently been intrigued by the following question: What is the difference between the pitch of the noise of dripping water between hot and cold water? For example, would cold water create a ...
1
vote
1answer
95 views
boundary limit conditions in 3D water surface simulation
As is discused on this post, taking some assumptions, the water surface can be simulated by a discrete aproximation of a grid of heights using this formula
Where:
HT is the new height grid
HT-1 ...
2
votes
1answer
72 views
Can small clouds reflect enough light to hurt your eyes/blind you?
I looked out my window a minute ago and immediately noticed a very bright spot where a cloud and a jet/plane trail met. The spot was so bright that I thought the sun was behind it because it left that ...
5
votes
1answer
54 views
Fresco in his “Future By Design” introduces drawing of underwater vessel and its front system of generating air bubbles. Is idea energy efficient?
I recently saw Fresco's Future By Design and noticed something miniature to investigate.
My notice regards about one of his illustration he describes in the documentary. Here is the link on youtube, ...
0
votes
1answer
123 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 ...
3
votes
1answer
107 views
How would one calculate the amount of water contained in a cloud?
So I was looking out the sky one day and I wondered how I would go about calculating how much water was contained in a cloud. I figured the following simple outline
1) We need to roughly know how big ...
4
votes
1answer
127 views
What would jumping into a pool and feeling cold be called? Conduction, or convection?
This was another question from my son's workbook. It said:
...
3
votes
1answer
159 views
Does $\lambda\nu = c$ hold for all the waves in the universe?
Are all waves in the universe the same as electromagnetic waves?
Basically, my question arises from an equation I found in my chemistry textbook:
$$\lambda \nu ~=~ c.$$
This states that the ...
2
votes
2answers
228 views
Will the siphoning effect help a system pump water upwards if the water's entry and exit points are at the same height?
I am looking to pump water from a pool up to a roof for solar heating (black plastic tubing) and then back into the pool with the original source water. Does the gravitational force of the water ...
0
votes
1answer
49 views
Action on Lard Oil
If water is mixed with lard oil and heated (creating some super-critical liquid with water), how does this affect the volatility of the mixture in comparison with its purity..?
So, My question is: ...
1
vote
2answers
156 views
How does blow-drying a mirror keep it from steaming up again?
After a hot shower, the mirror in my bathroom steams up. When I try to clear it with a towel, it immediately refogs. Yet once I use my hair-dryer, it will clear the fog and the mirror will stay clear.
...
0
votes
1answer
436 views
Is water considered a substance with low friction or high friction?
Like, for example, rubber is a substance with high friction, as an object with neither high or low friction would easily stop on it, and wouldn't skid. Ice is considered an object with low friction, ...
0
votes
1answer
79 views
The Ultimate Hand Dryer
I have come across many hand dryers that attempt to dry your hands really fast after you wash them. Here are two of them:
XLERATOR
http://www.exceldryer.com/
Dyson Airblade
...
-1
votes
1answer
141 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 ...
2
votes
2answers
281 views
Riddle: can you swim faster upstream than downstream (with respect to the water)?
A friend of mine posed a riddle to me:
A man swims upstream in a river, which is flowing at an unknown rate. He is wearing swimming goggles. At a certain point he loses his goggles. 10 minutes later ...
3
votes
1answer
178 views
Why is there a hiss sound when water falls on a hot surface?
Why is there a hiss sound when water falls on a hot surface? I have searched a lot, asked my teachers but none of them seem to give me the logical answer to it.
4
votes
1answer
266 views
How the bond angle of a water molecule is measured?
How the angle of a water molecule is measured?
The bond angle for water was first determined by vibrational and rotational analysis of its infrared absorption spectra. How is bond angle extracted?
3
votes
2answers
306 views
Why water is not superfluid?
My question is in the title. I do not really understand why water is not a superfluid. Maybe I make a mistake but the fact that water is not suprfluid comes from the fact that the elementary ...
1
vote
1answer
224 views
What makes water-droplet/dew stick to spider's web and what keeps them there?
How water-droplet/dew stick to spider's web? What keeps them there?
0
votes
1answer
477 views
What makes water boil?
Basically how boiling takes place?
Also like to know...
What makes boiling point alter at various altitudes?
Why bubbles rise through boiling water?
8
votes
2answers
920 views
273 + degree Celsius = Kelvin. Why 273?
Temperature conversion:
273 + degree Celsius = Kelvin
Actually why is that 273? How does one come up with this?
My teacher mentioned Gann's law (not sure if this is the one) but I couldn't find ...
1
vote
2answers
347 views
Why can't I evaporate water without wind, just heat? (not boiling,evaporating!) Or can I?
So here is the thing, I searched all over the internet for this but all the sources say that I need wind because the process of evaporation goes as follow:
Water particles at the top layer with ...
3
votes
1answer
222 views
Pascal law with two connected cylinders filled with water, and 50kg stones at both their ends
If I have two connected cylinders filled with water, and 50kg stones at both their ends (pressing both ends of the water) how much weight do I need to add on one side so that one of the stones reach ...
4
votes
0answers
131 views
How do I measure the temperature of a tiny water droplet?
How do I accurately (+/- 0.1 degrees Celsius or better) measure the temperature of a small (5 to 50 microliter) water droplet without noticeably affecting its temperature?
The mass of a thermistor or ...
1
vote
0answers
43 views
What phenomenon is responsible for the evolution pattern of waves created by waterfalls?
I have been fascinated lately by the pattern of the waves created by a waterfall in my town. Specifically, the pattern shows a gradual decrease in the density of the waves as they travel away from ...
3
votes
4answers
179 views
Water Jet Cutter and Laser
I watched a video of "Glass cutting" which uses a Water Jet Cutter. It was said that Cutting glass simply by machines would eventually crack it... So, They're using grains of sand (by placing a sand ...
4
votes
2answers
1k views
Why does earth look blue from outer space?
I know it's more than 70% water. But what has it got to do with earth's colour ?
3
votes
2answers
203 views
Why does it take until the middle of summer before lakes have warm water, but desert sand heats up in hours?
My sister asked me this question and I keep thinking that water would conduct heat much faster than sand. Hence the energy transfer of heat across the lake does not allow it to heat up soon. Sand on ...
1
vote
2answers
131 views
The physics behind The Great Flood [closed]
The book of Genesis floats (pardon the pun) some interesting numbers when discussing the Great Flood. For example, it rained for 40 days and 40 nights, and at the end of that time, the entire planet ...
1
vote
3answers
132 views
Water, can it break through temperature?
If water is heaten up to ridicilously high temperatures, is it possible for the atoms in the molecules to lose their bonds?
And if it is possible, isn't this some kind of chain-reaction?
Like you ...
1
vote
2answers
69 views
How to find out the compress happen when some force act on water/oil/air?
I need to do some calculation to find out whether my design works. I may use oil/water/air in my pneumatic cylinder (or you can call it hydraulic cylinder). Assume I have just a cylinder and I put oil ...
1
vote
2answers
155 views
Fluid Dynamics - Water Bottle Drink Mix: Air or No Air?
If you take an ordinary sized plastic water bottle full of water and pour a packet of powdered (or liquid) drink mix into it, Will shaking the bottle with the cap screwed on to dissolve the mix into ...
6
votes
1answer
675 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 ...
3
votes
1answer
428 views
Calculating time to heat cold water in bowl of hot water
How would I calculate the time it takes to heat a given volume of water to a given temperature with a given temperature T1 when it is submerged in a volume of water with a temperature T2
Estimation ...
5
votes
1answer
152 views
Distinctive properties of liquids
The molecules are closely arranged in solids, loosely arranged in liquids and are free to move in gases... But, Why are liquids (especially water) exhibiting these distinctive properties such as ...
3
votes
2answers
149 views
Does a fluid's temperature affect the way light passes through it?
For example, if I were to supercool water would it's refractive index still be 1.33 or would it be 1.31, the same as water-based ice even though it's still in liquid form?
2
votes
2answers
328 views
Why water will stay on a piece of toilet paper?
I think everyone has tried to blow air (breath) on toilet papers. The papers will get wet. I believe the holes diameters on a toilet paper should be much larger than diameters of water molecules. (The ...
0
votes
0answers
130 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) ...
7
votes
5answers
314 views
Zigzag flow of water along a vertical glass window
I've observed this behavior many times. When it rains, the rainwater will form vertical channels along a glass window. The flow of water is mostly confined within these vertical channels and the ...
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 ...
0
votes
1answer
142 views
Why does the water-pressure of my shower fall if I hold the shower head high?
I live in a very old house - build 1902 - in the 4th floor in the city of Karlsruhe (Germany). I have a shower and the gas-heater for the water is in it:
If I hold the shower head over some height ...
0
votes
1answer
75 views
how to stop water reaching up inside an under water structure (see video)
in this video at arround 0:47 they deliver the 'dry pots' to the under water lab, bellow the water and they seem to swim up into an opening where it is completly dry.. how is this dry, surly the water ...
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 ...
2
votes
1answer
102 views
Is my electric kettle collecting old water during the week?
I have an electric kettle at work. On Monday, it's empty and I pour in about 1.5 liters of water. I usually end up drinking about 1 liter per day and refilling 1 liter each morning.
At the end of the ...
1
vote
1answer
116 views
How would this rapid depressurization of water really behave?
An in-development game(Starbound) recently released a demo of their water physics. At about 39 seconds into the video, a volume of water in a container is released when the cap on the container is ...
