Surface tension Definition and 206 Threads

Hi .how can i calculate the molar volume and surface tension of nanoparticles ? shoud i have to calculate? or these parameters is available in tables or sth?

Hello How the surface tension is measured for molten metals? I have heard about the sessile drop, but it seems to be a very inaccurate method... Thank you for your time. Regards.

I want to demonstrate to flat earthers that water does indeed stick to a ball. If we want to do a scale model of the earth, at which radius will gravity overcome the surface tension?

I don't understand, when calculating the force to change the surface area of the film, how the length obtained in the diagram below is "l" (lowercase L). I understand that there are two surfaces to overcome, hence the factor of 2, but why is the length perpedicular to the force used and not...

Today I was speaking with a professor and he asked me, regarding fluids, what is pressure. I said force per unit area acting normal to a surface. He then asked what I meant by surface. I wasn't really sure how to respond. He also asked me what surface tension was. I said it is a force per unit...

Is there any entropic gain when the surface of a liquid is minimised? Per example, molecules "enjoy" maximum entropy when they are at the interior. Is this valid?

Homework Statement Consider a planar liquid-gas interface and a solid sphere partially immersed in liquid. A fraction of the solid surface area is wet by the liquid, call it ##A_{sl}##. The complement of the solid’s area is ‘wet’ by the gas, say ##A_{sg}##. There is also an area of contact...

While going through the derivation to find the surface tension of liquid i came with the formula which says that the surface tension is directly proportional to radius of the capillary so does that imply if we use a capillary with a greater radius so the same will give the different value of...

Homework Statement A hollow stirrer that has a diameter of 2.0 mm is inserted into a cup of water at 20∘C. The surface tension of water at that temperature is γ(surface tension) = 7.28×10−2 N/m. What is the mass of the water supported by the surface tension in the stirrer? Given: d=2 mm...

https://web.mst.edu/~numbere/CP/CHAPTER%203.htm I have trouble understanding why the length used in 3.1.1 is pir^2. My notes don't explain what length we use either.

Hi everyone, While studying surface tension I came across a(numerical example) problem which asks to find the force required to pull a circular glass plate of some given radius from the surface of water(assume plane of plate on water surface). Value of surface tension of water is also given in...

If you increase surface tension, the molecules at the surface are more strongly pulled into the center of mass due to the stronger attractive molecular forces. -Why is it that when surface tension increases in a liquid, its surface decreases in area, but its volume does NOT change? (Volume...

Hi I want to study the topic of surface tension for the purpose of solving problems. I have textbooks like Halliday Resnick and Young Freedman. But these books don't cover the topic of surface tension. If you know any free, open resources to study this topic, please let me know thanks

Homework Statement [/B] Water rises in a capillary tube to certain height such that the upward surface due to surface tension is balanced by 7.5 X 10-4N Force due to weight of the liquid. If the surface tension of water is 6 X 10-2Nm-1,the inner circumference of the capillary must be Homework...

Homework Statement [/B] The question is from chapter 9 of "Exercises in Introductory Physics" by Leighton and Vogt. The answer given in the book is ##R = 4.9 \times 10^{-5} \rm{cm}##. Homework Equations $$\sigma = \frac{\Delta P \cdot R}{4}$$ Where, ##\sigma## is the surface tension...

Hi everyone ! I'm currently working on a project for which I need to measure the advancing contact angle of a liquid on a solid, specifically the advancing contact angle of a molten thermoplastic on carbon fibers. My understanding is that there is a difference between dynamic contact angles...

It seems that both the capillary number and the Laplace number represents the relative effect of viscous forces and surface tension. Can anybody explain the difference between them? Thanks a lot. I have attach the Wikipedia- links to these two concepts...

I've been reading up on capillary action in a tube, and I have some questions: Say we insert a tube in a pool of fluid; Jurin's Law expression is ##h=\frac{2\sigma \cos \phi}{r\rho g}##. However, this height is not the height of the fluid measured from the bottom of the tube, but rather the...

I am struggling to understand the relation between surface tension and surfactants. When surfactants are added to say water they may have charge and head groups which influence surface motion due to repulsion and their size. However often when people refer to surface tension they refer to a...

i am trying to figure out the relationship between diameter of a drop of liquid, its density and its shape. Can somebody explain to me the following two lines?

During high school; I thought atmospheric pressure is so strong that plate will remain intact to the glass full of water when made upside down. But when we decrease the density of the fluid to the air; this phenomenon wont' work. That means atmospheric pressure is not only playing role in this...

Homework Statement Homework EquationsThe Attempt at a Solution Pressure inside bubble = 2T/R Buoyant force on bubble = ##\frac{4}{3} \pi R^3 ρ_w g ## But I do not understand how surface tension is exerting force on the bubble .Also I do not understand the direction of surface tension force...

Hi Guys... I have a small doubt regarding surface tension. When calculating the relation between Pressure Difference inside and outside a Droplet and Surface Tension, we multiply Pressure Difference with Cross Sectional Area of the Droplet and equate it to the Surface tension force. My doubt is...

Having trouble to understand a classical example of surface tension: Two balloons are connected to each other with a valve. If the surface tension of the two balloons is the same but one balloon is bigger than the other, when the valve is lifted open so the air in the two balloons is now...

From a textbook: I don't quite understand the part where the difference of densities is taken, could someone explain that for me? Thanks.

a thin film of water has surface tension due to the strong bonds present on the surface in order to counteract the net downward force and this increases the potential energy of the surface layer of particles therefore on a hydrophobic surface it forms a water droplet , my question is since it...

I was asked to explain how different factors affect surface tension. I can understand how temperature plays a role. 1) Contamination: Increase in contamination decreases surface tension. I tried thinking about it.I thought maybe the particles that contaminate the fluid get in the way and...

Homework Statement A match of length l=4cm is floating on the surface of the water from a glass. ( the water is at room temperature) If from on one side of the match we pour a few drops of soap, the match starts moving. In which direction is the match mooving and what force is acting upon it? (...

What will happen to a 110 pound man jumping from 80 feet into water feet first? I have done the math he hits the water at around 50 mph. How will this damage his body?

This is probably not a very intelligent question. When cotton wool gets wet, it shrinks. Is it possible to wet it without shrinking? I know that it shrinks because the water surface tension pull cotton wool together. These are some technique that I can think of - Add surfactant? But this will...

Hello, everybody. Is surface tension a conservative force? I think so, because it is related to surface energy. But I am not 100% sure. Thanks a lot.

Homework Statement (1)The gas inside a spherical bubble expands slowly so that its radius is increases from R to 2R. Atmospheric pressure is ##P_0## and surface tension is S. The work done by the gas is ___________ Homework Equations work done against surface tension ##W_t = S.\Delta A## where...

Hi PF! Simple question here, but if we have some fluid in, say a cylinder container, with a specified surface tension, to get force would we multiply the surface tension by the height of the cylinder (if it's standing up on a circular side)? I know we multiply it by some length, but I don't...

Homework Statement http://ocw.mit.edu/courses/mechanical-engineering/2-06-fluid-dynamics-spring-2013/assignments/MIT2_06S13_ps2.pdf Problem 7[/B]Homework Equations ##F=2*V/(a^2)*\sigma*cos(180-\theta)## The Attempt at a Solution With the problem statement given, it seems like the component of...

If I have a U-shape wire frame and it contains a straight sliding wire and I dip this in soap, a film forms between the sliding wire and the boundary of U shape frame. Why is the force due to surface tension F = 2Tl where l is length of sliding wire? They say there are 2 layers in contact...

If you increase the surface tension of a liquid, does it change the average bond strength of the liquid?

I was wondering, a ballpoint pen ink droplet is droped on water, it floats and moves, why? Is it density, viscosity, surface tension or something else. I am pretty stuck

What's the difference between surface tension and capillary force? Surface tension, a tensor, is the force per unit length. Again surface energy is the energy required to increase the surface area by one unit. Is the surface tension a capillary force?

1. Calculate the force needed to move the wire in the figure (Figure 1) if it holds a soapy solution (surface tension is 0.025 N/m) and the wire is 16.0 cm long. Express your answer to two significant figures and include the appropriate units. 2. γ(surface tension) = F (force) / l (length)...

I have went through the thread and looked at the explanations for surface tension, and I have also went online to about 10 different websites, but I have not yet been able to figure out this concept. I think it is just my inability to understand and I need perhaps a different way of explaining...

Homework Statement I need help on understanding a little part of the solution to this problem I've found on the internet. The problem Homework Equations Surface tension and pressure equations The Attempt at a Solution The solution My doubt: "The other component of the...

To what I know, surface tension is a force that appear at the interface between 2 bulk phases, and is parallel to that interface. Let consider a bulk of a fluid in the air. In the bulk of a fluid at rest, two sub-parts of a fluid exert a attractive force on one another due to surface tension...

So, the way I understand this is as follows : The alveoli (pretend they're bubbles) have diameters of the order of microns implying a massive pressure required to inflate them by the Young-Laplace equation. p_{in}-p_{out}=\frac{2\gamma}{r} However, the presence of pulmonary surfactant...

Homework Statement A loop of cotton floats on the surface of some water. A little detergent is dropped onto the water surface inside the loop, and the loop opens out and becomes circular. Explain why this happens. Draw a diagram showing the forces acting on a short length of the circumference...

when we try to measure surface tension of different concentrated solutions of n-butanol with a tensiometer, we have to go from lower to higher concentration and not the other way around. what is the reason for that?

Homework Statement Two bubbles, one of radius R and the other of radius 3R come into contact with each other. What is the distance between the centres of the two bubbles? Ignore the weight of the bubbles. Homework Equations p(inside bubble)= p(atm) + 4T/R where T is the surface tension and R...

Hi. I am doing a physics project and we have been told by my lecturer to find out how to determine the surface tension of a liquid using Poiseulle's Law and to describe an experiment on how to do so. I have no idea how you could do this because none of the variables in the law relate to surface...

Hello, I am looking for a general formula for the surface tension dependence with respect to temperature. I am aware of the Eötvös rule (http://en.wikipedia.org/wiki/E%C3%B6tv%C3%B6s_rule), but I only found data for water, and wonder if there are some for other compounds. Also, I wonder...

I am studying surface tension and I am summing up what I have learned through books till now: → On a molecular level, due to unbalanced forces on the uppermost level, the liquid molecules tend to go down the liquid. → As the molecules go down, the uppermost layer shrinks in size and tries...

Homework Statement A capillary tube of radius r = 0.3mm is filled with water. A water droplet is hanging on the bottom of the tube, as shown in the picture. The water level is h = 5.2cm. Estimate the radius of curvature of the droplet R. The coefficient of surface tension of water is σ =...