In a falling head permeameter test, the initial head (t=0) is 40 cm. the head drops by 5 cm in 10 minutes. The sample is 6 cm in height and 50 cm² in cross-sectional area and takes the area of the standpipe equal to 0.5 cm². Initially, the soil sample has a particle diameter of 2mm and water is flowing through the soil sample with a dynamic viscosity of 10^-3 pa-s. Now the soil particles are replaced with a particle diameter of 4 mm and oil is passed through this sample with a dynamic viscosity of 10^-5 pa-s. Calculate the permeability of soil after replacing soil particles and water with oil in __  x 10^-5 m/s