Question

The velocity distribution of viscous fluid through a pipe is

Answer 1

for a viscous fluid there will be fluid friction between the layers of fluid.
the layer or volume of fluid at the middle potion along the diameter of the pipe will have more motion. when we go outwards along the diameter the fluid friction will have its effect and the velocity of the liquid volume will be less there.
you can look for poiselles formula and other related topics for more details