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I did research on the topic and the Eötvös rule, but most of the results are just qualitative explanations or experiment-based proofs of the temperature-dependent function of surface tension.
Can anyone give me some hints on how to prove that linear...
There are two difficulties, first ##r(y)## is not known, the surface tension force ##F_{surface \; tension}## is not known either. We can write net surface tension force as
##F_{surface \; tension} = \int_0^H 2 \pi r (\sin \arctan \frac{dy}{dr(y)}) dy ##
Is there something else we could use to...
1.If the thickness of soap water surface decrease, whereas the concentration remain the same, how will the surface tension change?
2. If the membrane of soap water start to evaporate, its thickness become thinner and it’s concentration increase, How will the surface tension change?
Thank you!
I would think that a force due to surface tension would act upwards on the plate and not downward, as shown in the diagram I have come up with. The surface of water would act as a stretched membrane and therefore there would be a surface tension on water surface in contact with the bottom of the...
I think in the explanation below a very small element of the liquid at the line of contact between the horizontal solid surface, air outside the liquid and the liquid itself is being taken, and forces acting on such a small element are being shown. This very small element is to the left of shown...
Hello, I learned recently about alveolar surface tension, and the explanation provided in the course was not satisfactory, it said that it is due to the force that pushes water molecules of the outer layer to the inner layers, I don't understand why this force that pushes water toward the cell...
This is the Two-Balloon Experiment: https://en.wikipedia.org/wiki/Two-balloon_experiment#cite_note-MW78-1
The claim on Wikipedia which I am a little confused over is that when 2 balloons (at the 2 red points) are connected via a tube, the smaller balloon at a higher pressure would push air...
I am trying to find out what the smallest hole water will flow through. not a molecule of water, just water in general. Here is an example. I have a single walled cube that i 3d printed. When i put water in it, it leaks between the layer lines. I want to find out what the spacing between the...
Let's say we are pushing water down a needle, the contact angle between the needle and the water is ##\mathrm{45°}##.
For simplicity let's assume there is no gravity.
As the water is initially moving down in the left image, the angle ##\theta=\mathrm{45°}## and the surface of the water is a...
Summary:: Surface tension experiment
Does anyone have an idea about a SURFACE TENSION experiment to present as university class work?
An experiment that is not too "simple" and repetitive (like things floating under water), and that is well designed.
When small object such as needle is put on the surface of water it displaces small amount of water which creates a depression under the object. Such depression increases surface area of the water because of which surface tension tends to decrease it.
Explanation why surface tension balances the...
This method calculates surface tension based on force balance acting on the ring placed on the liquid surface: $$ F = G + \gamma L $$
where ##G## is weight of the ring, ##L## is wetted length of the ring which is equal to its circumference, ##F## is outer force of tensiometer acting on the ring...
The method to solving this is to equate forces along a portion of the balloon through which ##\sigma_L## acts, and another portion through which ##\sigma_t## acts. The former potion should be a circular cross section of the cylinder, while the latter will be a rectangular cross section. You will...
Summary:: Hi, I realized that surface tension is not covered in introductory physics textbooks. Where can I get a good introduction on surface tension?
*info provided should be about the same depth as topics in Halliday, Young.
Hi, I realized that surface tension is not covered in...
Hello! I am having unexpected difficulties with this problem.A friend showed me an article regarding the Lecomde ring method,and at the bottom was this little problem that to solve.I've done it like this.
$$ y = \frac{F}{4\pi r} $$ where F is the given force and r is = 0,0325 in meters. The...
Hello! To this I did what was recommended and this is what it looks like
$$ F = mg $$
$$ F = \rho * V * g $$
$$ F = \ rho * \pi^2 * h * g $$
Than for the surface tension I did the same thing to get an expression for F.
$$ y = \frac {F} {2 \pi r}$$
Than tried to get F out and than...
hello
i have a drip tube with water dripping and when i increase the flow rate or frequency of drips they get bigger/more massive.
i see the equation mass x gravity = 3.14(tube diameter)(surface tension)
my mass is changing but not gravity, 3.14 or tube diameter so surface tension must be...
I mention the details in the book (verbatim) in the form of a paragraph in green below. Later I ask my questions in blue font for better reading.
"Surface tension also explains why hot, soapy water is used for washing. To wash clothing thoroughly, water must be forced through the tiny spaces...
I was looking for on the internet for a while without a success.
If I know that the surface tension of pure oil is ##\gamma_o=A## and I know that the surface tension of pure water is ##\gamma_w=B##
so if I have a mixture of water and oil with surface tension ##\gamma_m=C## am I able to know...
A water drop of radius ##10^{-2}## m is broken into 1000 equal droplets. Calculate the gain in surface energy. Surface Tension of water is ##0.075 ~N/m##.
So, for the solution of the above problem we need to know how much surface area (combining all 1000 droplets) have increased from the...
I came across this diagram, the ##\gamma##'s are supposedly forces per unit length of the respective interfaces:
It's not clear what these forces are acting on. ##\gamma_{SL}## and ##\gamma_{LG}## look like they could be acting on a small bit of water right at the end, but I have no idea what...
why isn't Surface tension reliant on the composion of the atm?
For an instance; If you place a glass of water in a room with regular atmosphere or you place it in a room filled with other gasses. The coefficient of surface tension of the fluid will change? Maybe?
why isn't viscoty of a fluid...
So, I was studying about general properties of matter and topics like surface tension. I came across the phenomenon of water rising along a glass plate like in the picture. I looked for some mathematical interpretation of this on the internet and in some books.
[![enter image description...
Why does the force due to surface tension act parallel to the surface here?
I know that surface tension is a result of absence of cohesive force above the surface and thus the water molecules below pulls the surface down and keeps it like a stretched membrane.
If the surface is pressed as...
When calculating force due to surface tension across a hemispherical drop, we look at only the circumference and multiply it by the value of surface tension. When we know that it is the surface tension which is responsible for the curved surface of the liquid drop, why don't we calculate the...
According to this definition I am unable to understand why does surface tension acts tangentially to surface of contact of liquid and capillary tube. And is the force of surface tension balancing the adhesive forces which lead to capillary rise OR it is the reason behind the capillary rise?
I read the following two points:
Temperature is indirectly proportional to surface tension.
Adding impurities affect the surface tension of the molecules. Adding soluble impurities increases the surface tension whereas adding sparingly soluble impurity decreases the surface tension.
Why...
Imagine a bubble vibrating in air. Because it vibrates, it's interfacial area increases, thus new molecules are added and removed from the surface as it vibrates.
Consider a molecule is initially at position X_0 at the interface, and over a certain amount of time molecules squeeze and disappear...
If you have two different liquids (water and oil for example) mixed together and free floating without gravity, will they separate as they do here on Earth? If so, what property would determine the layering structure? I suspect they would separate, and if left undisturbed probably form a...
Homework Statement
Think of a drop of radius ##R## deposited on a fibre of radius ##b(b<<L)##.Find ##{\Delta{P}}##
Homework Equations
The relationship between excess pressure and the surface tension is given by Yong-Laplace equation,
$$\Delta{P} = \sigma{(\frac{1}{R_1}+\frac{1}{R_2})}$$
The...
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A closed cylindrical vessel filled with water (at room temperature) contains a small air bubble of normal pressure and volume ##V=1~{cm}^3## inside in it.The cylinder is then started to be rotated slowly with a small angular acceleration in a complete weightlessness (at a space station)...
I am trying to understand how fluids form particular shapes when put on a solid.
In the two figures,what are we taking as a system for the forces?
How the resultant of the forces influences the shape of the different fluids?
I am a high school student and currently studying Mechanical properties of fluid.
We are taught surface tension in a very introductory level and most of it is about liquid-gas surface tension.
We are taught that liquid-vapour tension is the atrractive forces that water molecules experience at...
Hi! Here's a tricky thermodynamics problem, I hope you can help with it.
1. Homework Statement
The boundary between two different materials can be divided into two different kind of phases: bulk phases and surface phases. For example, let's consider a boundary between water and air. We can...
Homework Statement
Hello everyone, I am doing an experiment and I've hit a snag with my calculations. I am looking at how concentrations of soap affect surface tension in water. I am have been using the capillary equation and capillary tubes for my calculations. I have practiced this method for...
I was reading Fundamentals of Inket Printing and it said the following:
"The surface tension in a liquid causes a force to act in the plane of the free surface
perpendicularly to a free edge in that surface."
Can someone explain to me what this means? What's the direction of the force? I have...
1. A small drop of fat floats on the surface of a liquid whose surface tension is s. Surface fat tension at the air-fat interface is s1, at the fat-liquid interface is s2. Determine the thickness of the drop if its radius is r.2. ##F=\sigma l##
##\delta P=\sigma (\frac 1 R_1 + \frac 1...
1. The films of the two liquids are separated by a bar of length l. The coefficients of surface tension of liquids are equal to s1 and s2, respectively. What force acts on the bar on the liquid side?(It is a rectangular surface of 2 liquids separated by a bar of length l)
2. Force=(surface...
1.The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of "lotus flower". Dirt particles are picked up by water droplets due to the micro- and nanoscopic architecture on the surface, which minimizes the droplet's adhesion to that...
1. Two coaxial rings of radius R=10 cm are placed to a distance L from each other.There is a soap film connecting the two rings(that looks like a cylinder which have different radii with z coordinate. (The rings lie in xy plane)).Derive a differential equation describing the shape r(z) of the...
Homework Statement
The surface of a liquid is just able to support the weight of a six-legged insect. The leg ends can be assumed to be spheres each of radius 3.2 × 10−5 m and the weight of the insect is distributed equally over the six legs. The coefficient of surface tension in this case is...
I attempted the question but it was wrong... I don't understand where i went wrong my working seems logical, can someone please help.
When a needle is gently placed on the surface of still water (γ = 0.0730 N.m-1) it can be supported by surface tension if the mass of the needle is small enough...
Homework Statement
The tension in the skin of the left ventricle of heart is 4.90 N/m. A cut is made on the left ventricle during surgery. How many stitches must be used to repair the cut? Each stitch will safely support a tension of 0.4 N.
Homework Equations
Surface tension = force/length...
What will be the area of common surface of two identical bubbles of radius R , i know there common surface will be flat as the radius of curvature of comman surface will tends to Infinity , but how do i relate with area of flat surface
I tried to use
Energy = Surface tension * area
And then...