As far as I understand it (which admittedly isn't very far), surface tension forces are made up by the tension-attractive forces of molecules at the liquid-gas/vacuum interface, such as those between hydrogen-bond-capable molecules in water.

But what happens when this liquid surface is in motion? I would assume that, given that there is no acceleration at, the surface tension doesn't really change much since they would be in some sort of "stasis", and the movement would only be that of all the molecules acting in concert. But say, if the molecules were not moving uniformly (but in a single direction), say the molecules in one part of the liquid body accelerates away from the other part, in some "pulling" motion.

What happens to the surface tension here?

  • $\begingroup$ What make You think that acceleration might influence suface tension? The forces caused by acc. will influence the form of the surface (making it more flat) but will not change the tension. $\endgroup$
    – Georg
    Oct 13, 2011 at 18:00
  • $\begingroup$ I was thinking about the distance between the individual molecules, which would affect then tension forces? $\endgroup$
    – Soyuz
    Oct 14, 2011 at 15:06

1 Answer 1


Surface tension is a consequence of fluid molecules that, at the interface with another fluid, have less neighbors than in the bulk fluid. Generally speaking molecules will always be more attracted to 'their own kind' and therefore the molecules with less neighbors at the surface will have an excess energy which results in a surface tension. The order of magnitude of this surface tension can be estimated as shown here on page 15-17

That said, this means that surface tension is the macroscopic effect of molecular forces. Because of the immense difference in scale at which these molecular forces and the inertial forces (your acceleration) work, the surface tension is not going to change at all.


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