Questions tagged [capillary-action]
162 questions
52
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3 answers
When water climbs up a piece of paper, where is the energy coming from?
Take a glass of water and piece of toilet paper. If you keep the paper vertical, and touch the surface of the water with the tip of the paper, you can see the water being absorbed and climbing up the paper. This climbing up is intriguing me. Where…
Malabarba
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How does a sponge "suck" up water against gravity?
If I take a sponge and place it in a shallow dish of water (i.e. water level is lower than height of sponge), it absorbs water until the sponge is wet, including a portion of the sponge above the water level. In other words, it seems the sponge…
Kyle Oman
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17
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4 answers
Molecular origin of solid-liquid and solid-vapour surface tension
I understand that surface tension arises at the liquid-vapour interface due to the asymmetric nature of long-range attractive forces and the short-range repulsive forces acting on the interface where there exists a gradient of density as we go from…
Apoorv Potnis
- 1,419
16
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4 answers
Why does string not wick down?
I regularly drink tea at work and I often reuse the tea bags (yes I know I'm a cheapskate). Yesterday afternoon I used a tea bag once and kept it in the cup in case I wanted another cup before I left. As it turned out, I didn't and the tea bag was…
AdamRedwine
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11
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2 answers
How is the water meniscus at the edge of a capillary tube?
Suppose we have a capillary tube in which water can rise to a height of x cm.
If we dip the tube such that the height above the surface is less than x, then how will the water meniscus be at the edge of the tube? Why?
Excuse the flat water at the…
user80551
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10
votes
7 answers
Capillary tube of insufficient length
I was wondering if we have a very thin glass tube placed in a tub of liquid and the portion of the tube outside the liquid is lesser than the height to which the liquid can rise because of capillarity, what will happen? Will the liquid overflow?
user34304
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10
votes
1 answer
Sandstone getting soaked with water
I have seen someone putting a sandstone in water. With only about 10% of the stone sitting in the water. One could see the stone getting soaked with water. So there must be a force, which lets the water climb up through the stone against…
Angelo.Hannes
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9
votes
2 answers
How is it possible for tall trees to pull water to heights more than 10m?
Which force actually drives water so high up, since pure atmospheric pressure will only get you up to about 10 meters if you're using suction and a long straw and yet tallest trees are over 100 meters ( trees do basically have long continuous…
Kugutsu-o
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9
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2 answers
Does capillary rise violate hydrostatic paradox?
If $p$ is a pressure and $p_A = p_{\text{atm}} + hdg,\,$ $p_B = p_{\text{atm}}$, is hydrostatic paradox violated, shouldn't $p_A=p_B$?
8
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1 answer
Physics of dunking biscuits
Together with my 5 years old assistant, after endless observations breakfast after breakfast, we finally decided to be serious about it, and quantify a remarkable property of biscuits in milk.
Surely, we are humbly trying to climb on the shoulders…
scrx2
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8
votes
5 answers
Why doesn't this capillary action generator work?
So I was doing a bit of reading.
Apparently the obstacle to generating energy from the forces driving capillary action is breaking the surface tension at the top of a capillary tube. It is just impossible to get the water to fall to drive a…
Owen Wall
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7
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1 answer
Capillary action and conservation of energy
When I dip a paper towel in a cup of water the water gets drawn up due to capillary action. How is this reconciled with conservation of energy, as it would seem on the surface that the potential energy of the system has gone up with no work being…
fbrereto
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7
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2 answers
What physical forces pull/press water upwards in vegetation?
Each spring enormous amounts of water rise up in trees and other vegetation. What causes this stream upwards?
Edit: I was under the impression that capillary action is a key factor: the original question therefore was: what are the fundamental…
Gerard
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7
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2 answers
Contact Angle In Capillary
One Professor recently told me that in an insufficient length capillary, the contact angle doesn't change, its an inherent property which does not change. If the edges of capillary are extremely sharp then tangent at a sharp point won't be defined…
Black Jack 21
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6
votes
2 answers
Why is the water level in the tube tilted instead of horizontal, like the water level in the rest of the cup?
The first photo is the original photo I took, while the second one has a faint red outline of the surface level of the water inside the tube and a faint blue line on the surface level of the cup. The circle is there to help locate the lines.…
