How Does Viscosity Affect Water Flow in Pipes?

[mr.]

Homework Statement

Water is in laminar flow, in a horizontal pipe 2.5 cm in radius. The pressure drop in a 20m section of the pipe is 3000Pa. The viscosity of the water is 1.2 x 10^-3 N *s/m^3. Calculate the velocity of the water along the axis of the pipe.

Homework Equations

The Bernoulli equation

The Attempt at a Solution

I attempted to apply the Bernoulli equation to this problem, but am not sure what to do with the viscosity of water. Every answer I have come up with is not correct.

How does the viscosity fit into this problem (if at all).

 

[Pyrrhus]

Aren't you forgetting about the energy lost to friction added to Bernoulli's equation?