4.5.12. a. The sum of the forces acting on the volume of liquid highlighted in the figure is zero. Using this fact, determine the height to which the liquid rises along a vertical wall. The contact angle is $\theta$. The surface tension and density of the liquid are $\sigma$ and $\rho$, respectively.
b. To what height will water rise along a vertical wall that it wets completely?
Solution
The sum of the forces acting on the volume of liquid highlighted in the figure is zero,so let's write force balance to the $x$ axis: