ABSTRACT
Stress Distribution in Water Below the Meniscus Figure 5.7(b) shows a capillary tube with its bottom end immersed in water. The pressure is atmospheric at points A and B. Since point C is at the same level as A, according to the laws of hydraulics, the pressure at C is also atmospheric. Since the point D which is just below the meniscus is higher than point C by the head he' the pressure at D must be less than atmospheric by the amount heyw. Therefore, the pressure at any point in water between C and D is less than atmospheric. That means, the water above point C is in tension if we refer to atmospheric pressure as zero pressure. The tension in water at any height h above C is given by hyw. By contrast, the pressure in the water below the free surface A is above atmospheric and therefore is in compression. The stress distribution in water is given in Fig. 5.7(b).
