Surface tension is the property of a liquid which enables it to resist tensile stress. Surface tension is denoted by σ (sigma). Surface tension is expressed in N/m (Newton/meter).

Surface tension is the property of a liquid which enables it to resist tensile stress. Surface tension is denoted by σ (sigma). Surface tension is expressed in N/m (Newton/meter).
Surface tension acts in the plane of the interface normal to any line in the surface.

A Newtonian fluid is defined as one with constant viscosity, with zero shear rate at zero shear stress, that is, the shear rate is directly proportional to the shear stress.