Surface Tension

Surface tension is defined as the force per unit length acting along the surface of a liquid. The formula for surface tension is given by: where is the force applied parallel to the surface and is the length along which the force acts. - The SI unit of force is Newton (N). - The SI unit of length is meter (m). Thus, the unit of surface tension is:

The angle of contact is determined by the relative strengths of cohesive and adhesive forces.
It is given by: When , we get .
Hence, the cohesive and adhesive forces are equal.