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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triangular symmetry of surface tension configuration of small grains on water

This is freshly ground pepper on water. Why is there a triangular configuration of the water around the pepper fragment? Surely all these pepper fragments have different shapes? You can clearly see ...
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34 views

Fluidics and surface tension

If a one cent coin is set carefully onto the surface of water horizontally (flat side parallel to the water surface). What are the relevant forces to determine if it would sink.
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0answers
35 views

Water floating on water [duplicate]

In the video made by the slo-mo guys as shown here, at time 1:47 comes a moment when a water droplet(almost completely spherical), is seen to 'float' on the surface of the water for a while. So why ...
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36 views

what is the mathematical expression of the water drop curve on the surface?

As a part of a high-school research about water drops on surfaces, I've been trying for a long time to find some theory that gives the expression of the curve, without any success. In fact, the ...
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0answers
41 views

Blueberries in water [closed]

I was washing blueberries recently and saw that some blueberries sank to the bottom of the bowl whereas others floated at the top. Then I poked some of the ones on top to push them fully underwater. ...
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1answer
92 views

Surface Tension and Its Direction?

Can Anyone explain what is the direction of Surface Tension? I studied it is along the Tangential plane to the surface e considered at the location of length element considered.. And within that plane ...
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2answers
162 views

Tennis ball in a glass of water

If you pour water into a glass half full and put a tennis ball there it would aim to its sides. But if you pour water completely full a ball would aim to center. It's definitely related to a surface ...
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1answer
285 views

Maximum hole size to stop a fluid passing through a solid

In a previous question, the following is answered in a general sense: Assume I have a inverse cone which holds 200ml water. I am going to cut the tip of the cone to create a small hole. How to ...
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55 views

How much of water's surface tension is entropic?

Water molecules on the surface of an air-water interface have preferred orientations that lower their energy. This implies that these molecules are not uniformly distributed in orientation space, ...
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25 views

What are the dynamics of the “break the surface tension with a drop of soap” experiment?

There's a common experiment exemplified in the first few seconds of this video: https://www.youtube.com/watch?v=WsksFbFZeeU You put some food coloring in the center of a plate of milk, then put a ...
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1answer
1k views

Why does surface tension of water-ethanol binary mixture decrease with increasing concentration of ethanol?

I was thinking that it must be due to weaker hydrogen bonding in ethanol than in water. But then I learnt that Raman Spectroscopy and viscosity measurements suggest that upto a certain ethanol ...
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1answer
39 views

Why surface tension behaves so differently?

When a needle (or any other object) floats on water, its acting upwards balancing the gravity. But when an object (or may be a needle suspended in water) submerged in water, it acts downwards. ...
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2answers
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Hydrostatic friction: why do water droplets stay at rest on an inclined glass surface?

This is a non-expert question on a (seemingly simple) text-book topic. The question is about "hydrostatic friction", defined as follows. Consider a drop of water resting on a flat surface. If the ...
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2answers
2k views

Can a droplet of water bounce back when it hits a water surface?

Is it possible that a droplet of water can bounce from the surface of a volume of water?
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1answer
54 views

Physics behind blowing soap bubbles

Is it possible, using the surface tension of a soap bubble, to calculate the maximum pressure (created by the air flow) it can withstand while still attached to the orifice to prevent it from bursting?...
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1answer
48 views

When does a liquid 'wet' a solid surface?

What is exactly meant when it is said that a liquid wets a solid surface. Has it got only to do with the contact angle ?
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1answer
69 views

Explaining the shape of a raindrop and a drop of mercury

I saw on wikipedia that the shape of a raindrop is explained by using Laplace pressure. But why? Since the drop is in motion, we shouldn't be able to use an hydrostatic law, am I wrong? ...
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0answers
13 views

A question concerning ad/absorption [duplicate]

Why does a bone dry sponge resist ad(ab)sorbing a liquid whereas a damp sponge readily soaks it up?
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0answers
27 views

What is the highest frequency for ripples on water

I want to transmit sound vibrations as ripples on water, as an experimental audio delay effect. Can I make ripples at audio frequencies, that will travel over about 10cm or more? How about other ...
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1answer
46 views

Surface tension in a balloon wtih water [duplicate]

Imagine such situation: We have an empty balloon. We put a long, narrow tube into this balloon and we fill it with water. Then, the volume (and surface) of the balloon will start to increase. The ...
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2answers
35 views

Why the Du Noüy ring method does not depend on the material the ring is made of?

Du No├╝y ring method is a way to measure surface tension. Why the measured force, $$F= 2\pi \cdot (r_i + r_a) \cdot \gamma$$ does not depend on the material the ring itself is made of? Wouldn't a ...
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1answer
46 views

What is the difference between pressure in water droplet and that in an air bubble?

The question is at least supposed to be simple but yeah, I need some detailed answers. I have tried thinking about it in the lines of surface tension but it seems what is required of me is more than ...
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2answers
49 views

Which side of liquid gas interface is at high pressure?

With respect to what(whether liquid or gas) should I consider that the convex side has higher pressure and concave at lower prsseure? As seen in the example of image it is given that air bubble inside ...
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5answers
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A cup of water in ZERO gravity

What will happen if I try to pour a cup of water in zero gravity, into another empty cup? Will the water come out of the cup? The adhesive force between the water molecules and the interior of the cup ...
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1answer
67 views

Torque and Force of Pulley fixed on side

If you had only 1 pulley that is connected to a rotating shaft, and which has a rope circled around it once, with a mass M on one side and with the rope fixed on the other end, how would you then ...
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1answer
37 views

Noncoalescingِ drops on vibrating liquid surface [duplicate]

if you set a dish filled with soapy water onto a loudspeaker or other vibrator and make vibration, When it oscillates, it is possible to hold small droplets on its surface for a long time. I mean, ...
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14 views

percolation permeability threshold in Helium before and after lambda point transition

There's an experiment demonstrating the properties of super-fluid Helium compared to normal fluid Helium, in which the Helium is put in a jar who's bottom is porous. The super-fluid can pass through ...
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Does surface tension play a role in planet's shape?

I'm thinking that when the planets and stars were forming along with gravity surface tension also could have played a role in making them spherical. Am I correct?
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62 views

Surface tension: the paper clip experiment

In the paper clip experiment, the surface tension of water prevents the clip from falling, thus we can assume it exerts a force of $mg$ (weight of clip) upwards. However, if you try to pull the clip ...
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1answer
33 views

How are probe liquids selected for Surface Energy measurements?

Why are water, ethylene glycol and diiodomethane generally used for surface energy measurement?
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1answer
92 views

Is surface tension the result of a pressure drop over the air-water interface or visa versa, for a two sphere system?

For a liquid bridge between two spheres the Young-Laplace equation states that: $\vartriangle p= \gamma\bigl(\frac{1}{R_1}+\frac{1}{R_2}\bigr)$ where $\vartriangle p$ is the capillary pressure ...
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2answers
45 views

why doesn't water in a inverted tumbler with its mouth covered with a porus cloth fall down ?

Is it due to the greater external atmospheric pressure acting upwards on the molecules or due to surface tension ?
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2answers
107 views

Why rough surfaces promote nucleation of CO2 in carbonated drinks?

Glassware with scratched/etched surfaces generate more bubbles (video 1, video 2). Why these rough surfaces allow easier heterogeneous nucleation?
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2answers
51 views

Why do bubbles group when one pops? [duplicate]

I was recently observing the way bubbles move as they pop and disappear. I noticed that when bubbles destabilize and pop, the remaining bubbles immediately surrounding it will move to fill its place. ...
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22 views

Beading of water on a hot surface

dropping water on a hot metal surface covered in dust results in the water forming beads. but if the surface is cold the water just flows over it. The temperature of the surface is roughly 120 degrees ...
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2answers
42 views

Does eq. of continuity hold in vacuum too?

When a streamlined flow of water flows down through an ordinary tap, it's cross-sectional area decreases according to eq. of continuity due to atmospheric pressure. If the same apparatus were to be ...
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1answer
312 views

What will be the shape of liquid if there is no gravitational force [duplicate]

We all know that liquid will take a shape of container in which its filled, but What will be the shape of liquid if there is no gravitational force?
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6answers
730 views

Why do liquids separate in space with no gravity?

I've seen videos of people in space (on ISS) who squeeze a bottle or something and liquid comes out, it then separates into smaller balls. Why is this surely it should stay pretty much together ...
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68 views

Forces causing capillary rise

I have learnt two derivations to calculate the height of the liquid column in a narrow capillary. Here is a derivation using forces and equilibrium : This is the exact derivation given in my book. ...
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50 views

How do impurities affect the surface tension of fluids? [closed]

I want to know what happens to the surface tension of fluids if we add impurities and the reason behind it.
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1answer
207 views

What exerts the force of surface tension, and what does it act on?

Let me start with the simple situation that I am familiar with. This question might be kind of long. In the situation shown in the above diagram, to keep the slider in equilibrium, we must exert a ...
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1answer
100 views

How does surface tension explain the floating needle experiment?

Part 1: After reading some explanation in internet I understood the fact that the molecules of water on the surface have no water molecules in the outward area so it feels a net force towards the ...
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2answers
96 views

Is surface tension characteristic of a fluid?

Does surface tension depend only upon the nature of the fluid or on other factors too like the liquid-solid or liquid-gas interface? I saw in my book definition that $$S = U/A,$$ where $U$ is the ...
0
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1answer
33 views

Why is the liquid surface concave when it wets a container?

As you can see in this diagram the surface of the liquid is concave, why is the part of the liquid surface adjacent to the container has higher height than the rest of the surface, is it because it's ...
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0answers
24 views

Gibbs isotherm and calculating interfacial tension change from first principles

Question: Is it possible for a solid particle to change the surface tension between two phases? (or: Does a solid particle have a chemical potential?) This question stems from the more fundamental:...
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1answer
50 views

Why is there pressure difference when the liquid surface is curved?

I also want to know why such pressure difference do not occur when the liquid surface is plane even though there are different mediums at both sides of the surface.
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33 views

Solving for diameter of a glass tube to hold water

I have a tube with length $l$. I then fill it with water. I then turn the tube upside down. What is the diameter as a function of $l$ such that the water does not spill out? I need to do a force or ...
3
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2answers
101 views

Glass tube diameter to hold water when turned upside down

If I have a glass tube that is closed at one end and has length l, how can I find the range of diameters that the tube must be so that the water does not fall out of the tube when the tube is turned ...