Here's the equation:

$\displaystyle \frac{\partial v}{\partial t} - \frac{\partial v}{\partial z} = 0$

Boundary conditions: Not much. v has to be bounded for all values of t, z.

There's a simple way to approach this...I just can't think of it. And yes, I could look up solution by characteristic curves but I'm convinced there is an easier way.

As it happens, I like the solution v = constant, but I need to see if there are any others.

Thanks for the help!

-Dan