Problem 2 In an experiment aiming to measure the pipe roughness (ε), pressure decrease of 40 kPa was measured across a pipe length of 250 m. The straight pipe has a constant inside diameter of 0.1 m. If the velocity of water (specific weight 9810 N/m³; kinematic viscosity: 1 x 10-6 m²/s) was 1 m/s, what is the absolute roughness of this pipe material? Assume a = 1.0 throughout.

Refer to Figure 7.24. The following data were collected during the field permeability measurement of a confined aquifer using a pumping test. Determine the hydraulic conductivity of the permeable layer. Use Eq. (7.49). Thickness of the aquifer, H = 4.5 m Piezometric level and radial distance of the first observation well: h1 = 2.9 m; r1 = 17.8 m Piezometric level and radial distance of the second observation well: h2 = 1.8 m; r2 = 8.1 m Rate of discharge from pumping, q = 0.5 m3/min

Calculate the R-value for the following materials: a. 4 in. thick brick b. 10 cm thick brick c. 12 in. thick concrete slab d. 20 cm thick concrete slab e. 1 cm thick human fat layer

Use Eq. (6.14) to determine the stress increase () at z = 10 ft below the center of the area described in Problem 6.5. 6.5 Refer to Figure 6.6, which shows a flexible rectangular area. Given: B1 = 4 ft, B2 = 6 ft, L1, = 8 ft, and L2 = 10 ft. If the area is subjected to a uniform load of 3000 lb/ft2, determine the stress increase at a depth of 10 ft located immediately below point O. Figure 6.6 Stress below any point of a loaded flexible rectangular area