I need an experiment about surface tension

[diogomcs]

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.

 

[berkeman]

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.

Welcome to PF.

(thread moved to the schoolwork forums from the technical forums)

So what are your thoughts so far? Please show us links to the reading that you have been doing about Surface Tension. There are plenty of simple experiments suitable for middle school and early high school, but it seems like you will need to look for more advanced experiments if you want to do this at the university level, IMO.

 

[kuruman]

Are you so supposed to design your own apparatus to measure surface tension? If so, design something simple that you make yourself and then do a series of repetitive measurements (don't knock them) that would answer questions like
1. How does surface tension depend on temperature?
2. How does surface tension depend on the density of the liquid?
3. How does surface tension change when you apply a thin coat of whatever to whatever you dip in whatever liquid?
Of course, for a university level study, you need to collect your data, analyze them, present an underlying theory that connects the surface tension (dependent variable) to the whatever (independent variable) and then see whether the theory matches your data. In short, I believe that what would make this a university-level experiment is not how you collect your measurements, but what you do with them.

 

[sysprog]

I suggest perhaps an experiment that demonstrates the hydrophilic/lipophilic nature of detergents, e.g. something that shows quantitatively how 'sodium lauryl sulfate' affects Brownian motion in an elementary-school 'drop of oil on water' demonstration.

 

[haruspex]

Maybe something based on https://en.m.wikipedia.org/wiki/Tears_of_wine

 

[sysprog]

Maybe something based on https://en.m.wikipedia.org/wiki/Tears_of_wine

I like this from that:

The phenomenon was first correctly explained by physicist James Thomson,[1] the elder brother of Lord Kelvin, in 1855. It is an instance of what is today called the Marangoni effect[2] (or the Gibbs-Marangoni effect): the flow of liquid caused by surface tension gradients.​

 

[bob012345]

You could do an experiment with the capillary effect.

https://en.wikipedia.org/wiki/Capillary_action

 

[sysprog]

You could do an experiment with the capillary effect.

https://en.wikipedia.org/wiki/Capillary_action

@bob012345, neato, when I was a little kid I imagined a 'perpetual motion machine' based on that $-$ it took me a while to recognize the ambient heat contribution to the otherwise 'isolated' system.