Water flows in a pipe at 0.015 m3/s. The pipe is 50 mm bore diameter. The pressure drop is 13 420 Pa per metre length. The density is 1000 kg/m3 and the dynamic viscosity is 0.001 N s/m. Determine i. the wall shear stress (167.75 Pa) ii. the dynamic pressure (29180 Pa). iii. the friction coefficient (0.00575) iv. the mean surface roughness (0.0875 mm)