Water at 20ºC flows at a velocity of 2 m/s in a 200-mm diameter horizontal ductile-iron pipe. a) Estimate the friction factor in the pipe, and state whether the pipe is hydraulically smooth or rough. b) Compare the friction factors derived from the Moody diagram, the Colebrook equation, and the Swamee-Jain equation. c) Estimate the pressure change over 80 m of pipeline. How would the friction factor and pressure change be affected if the pipe were not horizontal but 1 m lower at the downstream end?