Surface tension occurs due to the tendency of liquid molecules to favor their own kind. Surface tension is important in fluid multiphase systems typically at small length and velocity

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Surface tension and capillary rise

The expression for the height rise in a capillary tube is well known, and the surface tension of the liquid air interface is involved. But as I understand the adhesion force between the water and ...
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Why does a cork float to the side of a glass?

What is this physical phenomenon and when it's happen ? Please take a look at this picture: Notice: This is a cork ball attracted to sides of a glass of water
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543 views

How come a cork float to the side of a glass? [duplicate]

There's a not-so-recent video by a user named quirkology here, where he shows bets that usually work. From @2:19, he puts a wine bottle cap at the center of a glass ...
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How can I estimate meniscus height and surface area of liquid metal in a crucible at high temperatures?

Is there any methods that can estimate the height of meniscus or the surface area of liquid (liquid metal) in terms of temperature, pressure, viscosities of liquid and contacting gas, and the ...
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138 views

Coffee Straw Physics

When I put my little, cylindrical coffee straw into my coffee, the liquid immediately rises about half a centimeter up the straw without provocation. This is also the amount of coffee that the surface ...
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1answer
315 views

Why is Surface film a stretched membrane due to surface tension

Surface tension is the property of liquid at rest by virtue of which the liquid surface tends to occupy minimum surface area and behave like a stretched membrane. If surface tension is property of ...
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1answer
84 views

Why small droplet goes upward after pinch-off?

This small droplet moves against gravity. How to calculate its initial upward velocity exactly after pinch-off?
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1answer
99 views

If the surface tension is reduced to half(say by using a surfactant), what would be the effect on the size of an air bubble in the liquid

If I reduce the surface tension to half of the original value, what would be the effect on the size of an air bubble in the fluid? What would be the effect on buoyancy and drag forces? Also, if I ...
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2answers
146 views

Can a fruit fly move through a large bubble without popping it?

Assume what logistics you need to in order for something like this to be possible. Can a fruit fly move through a large bubble without popping it?
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2answers
817 views

Why is raindrop spherical in shape? [duplicate]

As the topic suggests why the raindrop is spherical in shape? Why it is not triangular or bipyramidal or tetrahedral? Is centre of mass or density of water related to it?
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2answers
55 views

When drying paint brushes washed with water, which way is the best to orient them?

After washing my paint brushes with soap and water and rinsing them, in order to avoid damage to the bristles and the ferrules and the wooden handle, is it best to hang them bristles down and let ...
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1answer
77 views

Does buoyancy change on smaller scales?

For baseball size objects on the order of centimeters across we have experience with what floats and what doesn't. A stick will float and a rock will not. But what if the rock were a grain of sand? ...
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Why does a pitcher with lemon juice have foam, while one with pure water does not?

Whenever I pour water into lemon juice (pouring directly from the tap into the pitcher, not quietly along its edge) I get a foam on top: The same pitcher with water (same water tap, pitcher, time ...
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1answer
1k views

What is the cause of the surface tension of the liquids? [duplicate]

What is the cause of the surface tension of the liquids? How to know the direction of tension force on the free surface of the liquid? I know that the surface tension is the force acting normally ...
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0answers
90 views

Can a liquid in a tube have a contact angle of 0 or 180 degrees with the tube?

When a liquid is placed in a tube, it makes contact with the solid walls and has a contact angle (the angle between the tangent to the liquid surface and the wall). What does it mean for the contact ...
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1answer
79 views

When metal solidified, why is its surface not flat like polished?

I expect that what one can see on the outside of a just solidified piece of metal is just the "raw" surface of the inner stucture. Solidifying metals or alloys arranges in partial christal latices ...
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1answer
261 views

Difference in electrons excitation in Au (111) between perpendicular and diagonal orientation?

In Au (111) single crystalline as shown in attached file, is there a difference the way electrons are excited when they are excited from perpendicular and diagonal orientation as shown in the figure (...
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0answers
75 views

Wetting the surface for soaking Nylon fabric in metal

I'm trying to create metal covered lace. My sister would use it as an artistic material. An interesting material A relevant point is that the mechanical rigidity of the metal is used, so it is not ...
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3answers
603 views

Size of a glass capillary for noticable capillary action

How big would a glass capillary have to be to have noticable capillary action? Also, does capillary action happen in plastic tubes?
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271 views

Meniscus attached to an inclined plate

To be more specific, suppose a hydrophilic infinite plate is stuck into a semi-infinite region of water, above the water is a semi-infinite region of air, when the plate is stuck into the water ...
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1answer
337 views

How does this capillary-action setup not become a perpetual motion machine?

If you have a very thin glass tube and you place it into water, let's say the water in the tube rises to the height of $x$ mm from the surface of the water. What would happen if you poked a hole in ...
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1answer
74 views

The shape of a bubble? [duplicate]

I have always wondered about a shape of a soap bubble. Why is it always spherical and not some other shape (like, cylindrical)? And why are the layers of the soap bubbles so thin? Also when someone ...
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2answers
390 views

Calculation of tension in a loop with force acting outwards

I'm having a few problems with understanding how to calculate tension in a loop. If I have a circular loop, and some force is applied uniformly radially outwards in such a way that the force acting ...
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1answer
413 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: where:...
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115 views

Does the value of Surface tension (the value of the constant) change with a change in surface area?

Surface Tension or ϒ (as in gamma) is a constant value for a particular fluid in fixed conditions. When we increase the surface area of the interface, more molecules pop up at the surface and ...
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0answers
51 views

Fluid flowing into small pores

I have some open porous foams with pore sizes ranging from 50-100nm. I want to flow water into this structure but even at 30 atmospheres it would NOT go in. I am looking for a way to calculate the ...
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1answer
188 views

Wavy stream of liquid

When pouring a liquid into a glass some streams have a wavy shape, like the one in the following photo: (Couldn't find a better picture, sorry.) What causes the stream to be of such a shape?
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2answers
377 views

Why pouring milk from a height makes a chain shape? [duplicate]

I have noticed a chain-like shape when milk is poured from a height into a cup. Actually the chain pattern repeats itself after some distance and again till it reaches the milk in the cup. Any ...
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2answers
290 views

How to find the maximum area of a slot that can keep water in a trough by surface tension?

Assume I have a trough of water 5mm deep. If I cut a slot (oval) into that trough what is the maximum size/area (length x width) that slot can be without leaking? This question is similar to Max. ...
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1answer
74 views

Does the contact angle of a drop depend theoretically on the size of the drop?

According to Wikipedia, contact angle depends on the hydrophobicity of the surface and on thermodynamic equilibrium. But how does it in theory depend on the drop size? In other words, how would a ...
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1answer
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physics of wet hair

I'm curious about the physics behind the clumping of wet hair. More specifically, how the amount of water in hair and distance between hairs affect the clumping process. I know intuitively that when ...
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Thermodynamic quantities of thin soap film on wire frame

Here is a question I am trying to solve. Sorry for the highlighting, it is not relevant. Here are my answers. For a), I would write $dE = dQ + dW$, following the first principle of thermodynamics. ...
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1answer
927 views

Why can liquid mercury sit on salt?

A video shows liquid mercury sitting on top of table salt. Even though the mercury is much denser, it does not sink to the bottom. Why does this happen? Is the mercury just so thick that it is like ...
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3answers
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About an upside down cup of water against atmosphere pressure

There is an experiment we learned from high school that demonstrated how atmosphere pressure worked. Fill a cup of water and put a cardboard on top of it, then turn it upside-down, the water will not ...
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2answers
215 views

What is the maximum net force of surface tension per gram of water?

I've always wondered how much force water exerted through surface tension. By maximum I mean the theoretical pulling/attracting power. Also, what would happen if you raised or lowered the power? ...
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1answer
127 views

Change in radius of a charged bubble

I was thinking about what'd happen to the radius of a bubble, if a charge is uniformly distributed over it. At the beginning, I thought that the bubble would expand, for sure, because of the like-...
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2answers
172 views

Foam patterns on espresso

When just prepared, an espresso has a thin layer of foam, known as crema, on its surface. As I move my drink from the bar to a table, the motion destroys the homogeneity of the layer, but I've noticed ...
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4answers
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Why is the pressure inside a soap bubble higher than outside?

Apparently, the air inside a soap bubble is under higher pressure than the surrounding air. This is for instance apparent in the sound bubbles make when they burst. Why is the pressure inside the ...
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1answer
190 views

Rate of Dripping of tube

My original problem was to discover the rate at which leaking taps dripped, and its relation with the tap's size, radius, etc. However, I have no clue how taps work, so I simplified the problem. ...
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3answers
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Walking on water

I was wondering about walking on water. I wonder if we can use surface tension to do this. Lets say I make a pair of shoes in shape which has infinite perimeter (e.g a koch snowflake) with glass. Now ...
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4answers
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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 capillarity,...
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Negative pressure, tension, and energy conditions

We have lots of common everyday experience with positive pressure, the canonical example is a gas. But other examples of positive pressure are easy to imagine: for instance, a solid that gets ...
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840 views

What could be added to tap water to reduce air bubble formation on a submerged object?

Submerge your hand in a bucket of water. Some air bubbles appear immediately and others add to the surface of the hand over time. Is there anything that could be added to the water to reduce the ...
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2answers
147 views

Can we break surface tension without physical contact?

It's my understanding that surface tension is caused by hydrogen bonding. My question is whether or not we can break that bond, without physical contact. Could we use electricity, light, heat, or ...
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2answers
2k views

Surface tension and soap bubbles

In a common experiment, you can make a paper clip float on water due to the strong surface tension. Adding just a tiny bit of soap immediately destroys the surface tension and lets the paper clip sink....
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1answer
111 views

Violation of conservation of energy… or not? [closed]

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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0answers
548 views

Under what conditions does Jurin's law work? (and what are its physical basis?)

I searched answer in wikipedia (and other sites) but I found disjointed and contradictory informations. In Jurin's law article they say that the law works if the radius of the tube is smaller than ...
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0answers
254 views

How much energy to overcome surface tension and create air bubble at an air/water interface

here is my question. Hope you'll help me ;-) Consider a test-tube, almost completely filled with water, and closed with a stopper. Turn it over and then remove the stopper. If the diameter of the ...
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2answers
2k views

What is the effect of surface tension on an air bubble inside water?

When an air bubble is formed inside water, and while it's still inside, does a force due to surface tension act on it? Why and where does this force act? I read somewhere that a bubble would detach ...
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268 views

How can a droplet of liquid float on the surface of the same liquid?

This can happen during the rain, or when pouring water. Sometimes small (1-2 mm) droplets of water float on the surface for some time (a few seconds) before coalescing with the big body of water. A ...