A capillary tube with a radius of 0.50 mm is vertically dipped into a pot of water. Find the difference between the pressure of the water inside the tube 5.0 cm below the surface and the atmospheric pressure. The surface tension of water is 0.075 N/m .

Step-by-step solution

The pressure just below the meniscus in the capillary tube is given by P₀ - 2T r , where P₀ is the atmospheric pressure, T is the surface tension, and r is the radius of the tube. The pressure P at a depth h below the meniscus inside the tube is: P = P₀ - 2T r + g h The difference between this pressure and the atmospheric pressure is: P = P - P₀ = g h - 2T r Given values are: = 1000 kg/m ^3 g = 9.8 m/s ^2 h = 5.0 cm = 0.05 m T = 0.075 N/m r = 0.50 mm = 0.5 10⁻³ m Calculating the hydrostatic pressure term: g h = 100