A horizontal cylindrical pipe has a part with a diameter half that of the rest of the pipe.

Part A

If VV is the speed of the fluid in the wider section of pipe, then the speed of the fluid in the narrower section is

V$4$V$4.$V$2$V$2\mathrm{.}2$V$2$V$\mathrm{.}4$V$4$V$.$