The basement membrane of the glomerulus has the following properties: Rp = 5 nm, the total glomerular membrane areas is 1.5 m2, the plasma viscosity is 0.002 Pa-s, ?p = 42 mmHg and ?? = 32 mmHg. The total volume of filtrate is 180 L/day. Find an expression for the fractional pore area versus ?z. If ?z = 60 nm, what is the fractional pore area?