Two Cylindrical Pipes Both Carry an Ideal Fluid (Zero Viscosity)

Multiple Choice

Two cylindrical pipes both carry an ideal fluid (zero viscosity) in laminar flow. Pipe A has radius R_A = 8 cm and flow velocity v_A = 2 cm/s. Pipe B has radius R_B = 4 cm and flow velocity v_B = 4 cm/s. Compared to the rate of flow in pipe A, that in pipe B is

A) the same.
B) half as large.
C) twice as large.
D) It depends on the length of the pipe.