tapered water pipe physics question?

Question

Water entering a house flows with a speed of 0.22 m/s through a pipe of 2.1 cm inside diameter. What is the speed of the water at a point where the pipe tapers to a diameter of 4.5 mm?

Answer 1

Volume flow is constant

V1A1=V2A2

V2= V1A1/A2
A=piD^2/4
V2= V1(piD1^2/4)/(piD2^2/4)
V2= V1(D1^2/(D2^2)
V2=0.22 x (2.1E-2)^2/(4.5E-3)^2
V2=4.8 m/s