# Problem: When a viscous fluid flows in a tube, its velocity is __________. A. The same everywhere B. Greatest at the center of the tube C. Greatest at the wall of the tube

###### FREE Expert Solution

From the Hagen-Poiseuille equation, velocity is given by:

$\overline{){\mathbf{v}}{\mathbf{=}}{\mathbf{\left(}}\frac{\mathbf{1}}{\mathbf{4}\mathbf{\eta }}{\mathbf{\right)}}{\mathbf{\left(}}\frac{\mathbf{∆}\mathbf{P}}{\mathbf{∆}\mathbf{x}}{\mathbf{\right)}}{\mathbf{\left(}}{{\mathbf{R}}}^{{\mathbf{2}}}{\mathbf{-}}{{\mathbf{r}}}^{{\mathbf{2}}}{\mathbf{\right)}}}$

From the equation, r is the distance from the center of the tube.

###### Problem Details

When a viscous fluid flows in a tube, its velocity is __________.

A. The same everywhere

B. Greatest at the center of the tube

C. Greatest at the wall of the tube