Determine the value of the coefficient of permeability
A glass cylinder 5 cm internal diameter with a screen at the bottom is used as a falling head permeameter. The thickness of the sample is 10 cm. The water level in the tube at the begin of the test was 40 cm above tail water level and it dropped by 10 cm in one minute whereas the level of tail water remained unchanged. Verify the value of the coefficient of permeability.