In a hemodialyzer (artificial kidney), blood (density = 1.06 g/cm³) flows through a bundle of hollow fibers, a salt solution flows around the outside of the fibers, and waste products transfer from the blood through the fiber walls to the solution. A typical blood flow rate through a hemodialyzer is 350 cm³/min, and the associated friction of flow is 45,000 cm²/s². The hemodialyzer is 30 cm long (between the blood inlet and blood outlet), and the blood inlet tubing and blood outlet tubing have the same diameter. What is the blood pressure drop (in units of mm Hg) from inlet to outlet if the hemodialyzer is oriented
a. horizontally (with the blood inlet and blood outlet at the same height)?
b. vertically, with the blood inlet at the bottom and blood outlet at the top?
c. vertically, with the blood inlet at the top and blood outlet at the bottom?