Surface tension effects of surface tension can be seen with ordinary water: Surface tension is visible in other common phenomena, especially when surfactants are used to decrease it: Surface tension, represented by the symbol "γ" (alternatively "σ" or "T"), is measured in force per unit length. Its SI unit is newton per meter but the cgs unit of dyne per centimeter is also used. For example, Surface tension can be defined in terms of force or energy. In terms of force: surface tension of a liquid is the force per unit length. In the illustration on the right, the rectangular frame, composed
Liquid on the sides of a container as well as on anything within the liquid itself. This pressure is transmitted in all directions and increases with depth. If a liquid is at rest in a uniform gravitational field, the pressure, "p", at any depth, "z", is given by where: Note that this formula assumes that the pressure "at" the free surface is zero, and that surface tension effects may be neglected. Objects immersed in liquids are subject to the phenomenon of buoyancy. (Buoyancy is also observed in other fluids, but is especially strong in liquids due to their high density.) Unless