The following data were obtained for flow of 20°C water at 20 m3/hr through a badly corroded 5-cm-diameter pipe which slopes downward at an angle of 8°: p1 = 420 kPa, z1 = 12 m, p2 = 250 kPa, z2 = 3 m. Estimate (a) the roughness ratio of the pipe; and (b) the percent change in head loss if the pipe were smooth and the flow rate the same.