Following are the results from the liquid and plastic limit tests for a soil. Liquid limit test: Number of blows, N 15 Moisture content (%) 42 20 40.8 28 39.1 Plastic limit test: PL = 18.7% a. Draw the flow curve and obtain the liquid limit. b. What is the plasticity index of the soil?

Water at the rate of 1 kg/s is forced through a tube with a 2.5 cm inner diameter. the inlet water temperature is 15°c, and the outlet water temperature is 50°c. the tube wall temperature is 14°c higher than the local water temperature all along the length of the tube. what is the length of the tube?