Surface tension Definition and 192 Threads

Homework Statement Homework Equations The Attempt at a Solution Honestly, I don't have any idea on this. As far as I remember, the usual practice is to equate the excess pressure equal to ##2T/R## (where T is the surface tension and R is the radius of curvature, this may be wrong...

Homework Statement (Ans: ##\pi F/(2L)##) Homework Equations The Attempt at a Solution I am not too much familiar with these type of questions so I don't really how to begin with this. Also, I don't understand the question here. Do we have to consider it in the vertical or...

I gave away the answer in the title, but still, this is a pretty cool demonstration of what happens when you wring-out a washcloth in space: https://www.youtube.com/watch?v=lMtXfwk7PXg

Hi, I have a question, because I am confused with the definition of surface tension. In my book it is defined as follows: "Surface tension is the energy required to increase the surface area of a liquid by a unit amount" What do they mean with increasing the surface area, how do you do...

I was solving a problem from fluid mechanics... But that led me to question my conception abt surface tension... The problem stated that the max force needed to uphold a needle(ignore its weight)from the water surface is F... The needle is L m long... What is the surface tension? They found...

The buoyancy force is defined as the difference in pressures on the top and bottom of an object submerged in a fluid. When an object is pushing on the top surface of a fluid from underneath, the force of surface tension begins to act downward on the object, preventing it from breaking the...

Hi, I wasn't actually sure where I should post this. I am trying am experiment where I need to briefly break the surface tension of a droplet to then allow another droplet to form in it's place. I don't want to use any chemicals as that would effect the test further down the line. Is...

Hi, I wasn't actually sure where I should post this. I am trying am experiment where I need to briefly break the surface tension of a droplet to then allow another droplet to form in it's place. I don't want to use any chemicals as that would effect the test further down the line. Is...

Hi there. I have found the surface tension for liquid etanol on a given problem. Then the problem says: supposing that the coordination number for etanol is 12, what value does the intermolecular interaction energy has? I have ##\gamma=21,26355\frac{dyna}{cm}##, gamma is the surface tension that...

Please read it , and tell whether it is correct. No explanation also okay. Thanks Surface tension of water.  Cohesive and adhesive forces  Cohesive force is the forces between water molecules.  Molecule in the bulk liquid is attracted by other molecules in all direction due to the...

Hi, Homework Statement A square frame with a thin crust/layer of liquid with surface tension γ is given. Into the plane of the frame an elastic wire of circular shape with radius r_0 is inserted. The thin crust/layer of liquid is then burst (by pricking) and as a result of the force of...

Homework Statement When calculating the difference in pressure inside a spherical raindrop, the force exerted by the surface tension is calculated to be 2pi*R*gama, where R is the radius of the drop and gamma is dE/dS (dyne/cm). When the shape of the raindrop is said to be that of a torus...

[FONT="Century Gothic"] I need to find the surface tension of water and how it is effected by different kinds of soap. I am unsure how to find the surface tension of a liquid though. Please and thank you! xoxo Best wishes! NERD OUT. ∞ Homework Statement ... Homework Equations ...

How would decreasing ocean salinity affect surface tension, and how would this reduced surface tension affect coastal zones? Seems to me that a decrease in salinity will decrease surface tension because density decreases with decreasing salinity. So I would think decrease in density would...

http://en.wikipedia.org/wiki/Surface_Tension Could someone help me solve the capillary rise method equation, with a worked example: y= hpgr/2 Thank you soo much

Homework Statement The pressure by the walls of a bubble is 4σ/r (where σ is the surface tension). The radius r of 2 bubbles is measured. After that you bring the two together by connecting them with a straw (the smaller bubble has higher pressure and gets smaller, while the bigger bubble...

Hi everyone. I have a very basic question here. What exactly cause surface tension? On hyperphysics website, it say surface molecules develop stronger bond with each other. 'Those on the surface have no neighboring atoms above' But what cause this stronger bond? Stronger bond is a result...

Homework Statement Two soap bubbles of equal radius 'r' coalesce isothermally to form a bigger bubble of radius 'R'. If the atmospheric pressure is P0, find the surface tension of the soap solution. Homework Equations Surface energy = surface tension x increase in area (W = T.ΔA)...

Homework Statement In some cases waves on deep water are driven by surface tension effects and not by gravity. The surface tension is the energy per unit area of the water surface. The area of the water surface increases by a factor proportional to (Ak)^2 in the presence of a wave amplitude...

there is a liquid in a capillary tube. The tube pulls the liquid because of adhesive force and liquid pulls the tube because of surface tension. Will both the forces be equal? according to Newtons third law-yes I don't understand this. IF this is the case then whatever the substance tube is...

So I'm working on a chemistry lab determining Avogadro's constant with a fatty acid monolayer on a beaker of water, and my calculations are all work out to around 1.3*10^23 (ie a sixth of what they should be). The lab said "fill the beaker with water until it spills over". In doing so, I ended...

Hi all, Typically, we know that the surface tension for water is about 72mN/m at RT. so do this mean that the surface tension over the whole droplet is exactly the same? Moreover, we know that the Laplace pressure may be different over the whole droplet as the curvature in different parts...

consider a U shaped wire piece. a movable wire is fixed on it and their is liquid bubble in between them. If we move wire through distance l what force we need to apply surface tension basic formula is F=Sl. so it should Sl but it is 2Sl i cn't understand can you please help.

Let σ be the surface tension ... I got to know that the excess pressure for a liquid-gas interface with radii of curvature (see http://en.wikipedia.org/wiki/Surface_tension#Surface_curvature_and_pressure ...the part on Surface curvature and pressure and Young-Laplace equation). is given by ΔP=...

I'm a little very confused about the origin of surface tension. As I understand it, surface tension is a force on the surface of a liquid which is directed parallel to the surface, correct? But the explanation of surface tension is that molecules at the surface are not covered by other molecules...

Hey guys, I'm working on a project which demonstrates the venturi effect, by flowing gas through a nozzle (which is housed in a 2 piece housing) and it flows out the exit, the air is picking up water along the way. We have noticed that water droplets are forming in the corners of the...

Homework Statement While a person breathes in, a typical alveolus expands from a radius of 0.13 x 10-3m to 0.15 x 10-3m. The alveolus behaves as though it has a single surface which is described by P =2γ/r ote the following. The gauge pressure in the alveoli of the lung is denoted Palv...

I would really appreciate some help with this! h= (L) r=(L) p=(ML-3) g=(LT-2) I just don't know what to do with the directly proportional sign. Should I isolate the surface tension before or after adding the constant?

Can somebody tell me how to differentiate a large scale to a small scale? I want to know what he/she is based on. What if you had to compare the scale of large and small bodies using gravity and surface tension, what would be your first move?

We're learning about the basics behind surface tension in chemistry and I'm having trouble applying what I learned. I've gone through my class notes over and over for the past 4 hours and I can't figure out how to even begin to solve the problem! Can I have some help understanding the basics...

Hello, I've been studying for a physics exam and this problem has driven me almost nuts. It's incredibly simple and yet I can never get the exact answer. I've seen it in several variations (different numbers, asking for a different variable) and in all cases it makes no sense. Here it is...

On my test it asked what causes surface tension. The teacher says the correct answer is that "the intermolecular forces are stronger at the surface of a liquid than in the bulk of the liquid." Is that correct?

what is the relation between surface tension and pressure ? are they same dimensionally? can they be equated?

Homework Statement An air bubble rises in water and makes contact with a container wall. Does contact with the solid surface change the bubble volume even if the surface is neither hydrophilic nor hydrophobic, but forms a contact angle of 90 degrees with the air-water interface?(Neglect...

Hello. I'd like to ask: does syrup increase or reduce the surface tension of water? Thanks.

hi =D i observed something interesting during the experiment. i immersed a normal temperature wire in a chalet filled with water and particles (lycopodium, glitter) floating on the surface. the original problem is to immerse a "hot" wire (2011 IYPT problem) but i was curious what would...

Homework Statement In this problem, the surface tension S represents the work done to the water when increasing the water's surface area. The vaporization temperature Qvap represents the energy needed per volume unit to vaporize water at 100 degrees Celsius. We imagine that water molecules...

Clarification on surface and interfacial tension? Interfacial tensions are less than surface tensions... The reason given in book is :- because the adhesive forces between two liquid phases forming an interface are greater than when a liquid and a gas phase exist together. I don't...

What would be the best way to find the surface tension of a water-based solution with an experiment without using any expensive/specialist equipment? I thought that using the capillary rise method would be a pretty good idea as it isn't too hard to measure the variables needed to calculate...

In the image that I've attached with this thread you can see proof of serface energy+surface tension. This scaned image is from my school book. When I was going through this topic I wound that in this increase in surface area = 2lx which according to me isn't reasonable. I discussed about it...

Homework Statement An air bubble of radius R is formed on a narrow tube having a radius r where R>>r. Air of density ρ is blown inside the tube with velocity v. The air molecules collide perpendicularly with the wall of bubble and stop. Find the radius at which the bubble separates from the...

Suppose a uniform cube of wood floats on the surface of water. Water wets it completely. Will it be buoyed up or down by surface tension? The force of surface tension is tangential to the liquid surface (along the surface of liquid). So I think there is no effect on buoyancy of cube due to...

Homework Statement A glass capillary sealed at the upper end is of length 0.11m and internal diameter 2 x 10^-5 m. The tube is immersed vertically into a liquid of surface tension 5.06 x 10^-2 N/m. To what length has the capillary to be immersed so that the liquid level inside and outside...

Surface tension is a property of two different substances. The surface tension of water against air under different conditions is given in many textbooks and data handbooks. However, if the air is replaced by, say, hydrogen, what will be the surface tension? Where will I have to look for the...

I read to today that soap bubbles explodes due to surface tension regardless of other forces experienced on the bubble. how does surface tension does that? does it "drive" the bubble to go larger until it explodes? Thanks, Omri

Homework Statement First part of the question was "Why is it possible to float a wax-coated stainless steel needle on the surface of water?" and I've already answered that, but I'm having trouble with the second part of the question, which is: If the surface tension at the interface is...

See link: http://www3.interscience.wiley.com:8100/legacy/college/cutnell/0471713988/ste/ste.pdf. When defining surface tension, the article makes reference to a C-shaped apparatus. Why is γ = F/2l and not F/l? It says something about there being two surfaces, but it seems to me that because...

I start working with the OCA15plus tensiometer and I don't know what the three red lines that appear in the program SCA20 means and how should I position them in the image of the drop on an analysis of surface tension by pendant drop method, for example. Can anyone help me?

Homework Statement (Sorry if this topic belongs to another forum.) The definition of surface tension is the force exerted parallel to the surface of a liquid along a line of unit length, perpendicular to the line. So if, hypothetically, when you place a needle on the surface of water, the...

can anyone explain what actually surface tension is?? I am confused about surface tension. Everywhere it is written that due to unbalance of forces at surface the molecules at boundary tend to move inwards and thus surface tends to take minimum area as possible. This is ok but it is also...