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Capillary action height

How to calculate height of the liquid (let's say it's water) in the capillary (so height of capillary action) if you only have r given, r = 0.3 mm - r is radius of capillary. The equation I would use ...
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61 views

Violation of conservation of energy… or not?

The work done by surface tension is double the increase in potential energy. This is a clear violation of conservation of energy. What is the flaw here? Work done by surface tension is \begin{align} ...
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“Troll physics”: What is wrong with this perpetual machine? [closed]

I think this will not work because the water can't flow out of the tube. (But what if we make the other end a little wider, will the water stop right before that part? What confuses me is that even ...
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where does the energy for capillary action come from? [duplicate]

I think capillary action occurs because water molecules have a little magnetic field with poles so they can stack up on each other somewhat. When it happens though, where is the energy derived from to ...
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Capillary action column height in a tube fitted inside another tube?

I was thinking about how would capillary action change in a tube (classic example) and in a tube fitted inside another tube (considering water as the liquid involved). Height of liquid column: ...
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1answer
103 views

Capillary action meniscus height in a tube fitted inside another tube?

I was thinking about how would capillary action change in a tube (classic example) and in a tube fitted inside another tube (considering water as the liquid involved). Height of liquid column: ...
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3answers
107 views

Will a drop of liquid flow from from the wide opening to the narrow opening of a thin funnel by the effect of air pressure?

We have a funnel that is thin enough to keep a drop of liquid inside it as shown in this figure. Assuming that the funnel is placed on a horizontal table, will the drop flow from the left side to ...
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3answers
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How is sweating a pipe an example of capillary action?

I learned how to sweat a pipe today from my father. If you're not familiar with the process, this might help. One thing that jumps out at me is this line (from the above link, as well as my father's ...
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73 views

Capillary in a slanted tube with a bend

So I've read a question on here about Capillary action in a slanted tube, but my question goes a little further. Firstly though, could someone explain to me what is meant by the only answer to that ...
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1answer
185 views

Can capillary forces be used to make hydro electricity?

Could a device with very thin columns of glass or something that attracts water more be used to pull water up and then release it to drive generator and perhaps add vacuum. I have been wondering ...
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1answer
113 views

Ink in a pen on an artificial satellite

In an artificial satellite, a space traveler tries to fill a pen by dipping it in ink. The amount of ink filled in the pen as compared to the amount of ink filled on the Earth's surface will ...
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764 views

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 ...
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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 ...
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414 views

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 ...
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1answer
2k views

Problem understanding the capillary action equation

As you know the equation of capillary action id given by: $h=\dfrac{2\gamma\cos\theta}{\rho gr}$ Where: $h$ is the height the liquid is lifted, $\gamma$ is the liquid-air surface ...
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1answer
147 views

Why do new towels dry better after a few uses?

Most of you will be familiar with the phenomenon: you have bought a new towel and you first have to wash it or use it a couple of times before it starts to work properly, i.e. dry your body after ...
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2k views

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 ...
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1answer
125 views

Equidistant coffee rings in a mug: pinning boundaries coupled with migration of solute or just sip volume?

I understand that you get coffee rings on a table as a result of solute migration (solutocapillarity) towards the pinning of the circumference of the coffee ring [Deegan et al.]. Below is an ...
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1answer
3k views

Surface tension and capillarity

The cause of surface tension is said to be asymmetry in the forces experienced by the molecules at the surface due to different interactions with air and liquid, but then the same argument also ...
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4answers
703 views

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 ...
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1answer
237 views

Capillaries in series

The velocity of fluid of viscosity $\eta$ through a capillary of radius $r$ and length $l$ at a distance $x$ from the center of the capillary is given by; $v=\frac{P}{4l \eta }(r^2-x^2)$ (where $P$ is ...
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1answer
599 views

Capillary engine is impossible?

I read some articles saying that it is not obvious (or maybe impossible) to generate energy using capillary action. On the other hand in my understanding trees uses capillary action to extract water ...
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1answer
289 views

How does a piece of paper manage to pump out the water from a bowl

When we go to bed at home, we started to put a bowl of water on the radiator (the air gets a bit dry). By instinct I put a soaked piece of paper (e.g. toilet paper) into the bowl and let it touch the ...
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2answers
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Capillary action and conservation of energy [duplicate]

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 ...
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3answers
3k views

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 ...
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2answers
767 views

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 ...