Consider steady flow through the duct with the circular cross section illustrated below.

Use the conservation of mass to find $U_2$ in terms of $U_1,$ assuming $\frac{D_1}{D_2}=6\mathrm{.}000$ and

the flow is steady, compressible, and uniform across the entrance and exit of the duct

with $\frac{T_2}{T_1}=5$ and $\frac{P_2}{P_1}=2.$