Unbalanced Young force

Each contribution in equation (7.39) comes from the corresponding part of the drop schematically presented in Figure 7.14. Since the total dissipation can be related to the product of the unbalanced Young force F by the line velocity, i.e. 

How can the spreading law V dd) be explained The macroscopic force pulling on the droplet is the unbalanced Young s force... 

The vertical component is balanced by the elastic force due to deformation of the solid, whose amplitude is microscopic (of the order of A), li 9 is not equal to 9e Young s forces are unbalanced and its contact line moves (Sect. 1.2.7). is called the dynamic contact angle. 

At the interface of water and air, there are unbalanced forces owing to the surface tension of the fluid. In the unsaturated zone, this transition zone is known as the capillary fringe or tension-saturated zone and these unbalanced forces result in capillary rise of groundwater and dissolved constituents. Assuming a constant hemispherical fluid meniscus and pore radius, the equation of Young and LaPlace can be combined with an equation for hydrostatic pressure to produce a relation for computing the capillary rise of fluid ... 

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