1. At 60°C the surface tension of water is 0.0662 N/m and that of mercury is 0.47 N/m. Determine the capillary height changes in these two fluids when they are in contact with air in a glass tube of diameter 0.55 mm. Contact angles are 0° for water and 130° for mercury.
2. Determine the diameter of the glass tube necessary to keep the capillary-height change of water at 30°C less than 1 mm.