Question $2$

Plot the streamlines for the following velocity fields. Feel free to use the software package of your choice, or do it by hand. The first corresponds to a "vortex," $($like looking at a tornado from above$)$; the second corresponds to a "stagnation point," $($like a flow running into an obstacle$).$

$u_z=\frac{y}{\sqrt[\phantom{2}]{x^2+y^2}}$

$u_y=-\frac{x}{\sqrt[\phantom{2}]{x^2+y^2}}$

$u_z=x$

$u_y=-y$