A field sample of an unconfined aquifer is packed in a test cylinder. The length and the diameter of the cylinder are 50 cm and 6 cm, respectively. The field sample is tested using pure water (at 20 oC) for a period of 3 min under a constant head difference of 16.3 cm. As a result, 45.2 cm2 of water is collected at the outlet. Determine the hydraulic conductivity of the aquifer sample? On further observation it was noticed that the sample has a median grain size of 0.037 cm and a porosity of 0.30. Evaluate the validity of Darcy’s law?