1. Water at 20-C flows through a 12-mm-diameter pipe on a downward slope so that Re ¼ 2000. What angle would result in a zero pressure drop?
2. Water at 40-C flows in a vertical 8-mm-diameter pipe at 2 L/min. Assuming a laminar flow, calculate the pressure drop over a length of 20 m if the flow is (a) upwards and (b) downwards.