Properties of problem: friction-less @all locations, non rotating planet
So I am told that a steady current has the velocity components $(u,v,w)$ and $u$ mainly depends on x.
Also this was stated in the problem and I have no idea what it means $O(u) >> O(v,w)$. What is $O$?
$x1 = 0m$, $x2=50,000m$
$Depth=500m$
I'm told that the depth drops by $.9m$ and that $u1=0.3 m/s$ at $x1$
I need to find $u2$ at $x2$, however since the problem states that $u$ mainly depends on x do I need to include $y$ into calculating $u$, and if so what equations should I focus on?
If I don't need to include $y$ in calculating $u$ then wouldn't $u1 = u2$, but that seems too easy.