📖 Explanation
Given Data (from the figure): Pipe A: DA=2 m,LA=100 m,f=0.01 Pipe B: DB=1 m,LB=200 m,f=0.01 Frictional Head Loss Formula (Darcy-Weisbach): hf=f⋅DL⋅2gv2 Since discharge is same, velocity is related to diameter: Q=A⋅v⇒v∝A1∝D21⇒v∝D21 So, v2∝D41 Ratio of head losses: hf,Ahf,B=f⋅DALA⋅DA41f⋅DBLB⋅DB41=LALB⋅DB5DA5 Substitute values: hf,Ahf,B=100200⋅(12)5=2⋅32=64