Streamlines are given in Cartesian coordinates by the equation. [ psi=Uleft(y-frac{y}{x^{2}+y^{2}} ight) . quad x^{2}+y^{2} geq 1

Streamlines are given in Cartesian coordinates by the equation.

\[ \psi=U\left(y-\frac{y}{x^{2}+y^{2}}\right) . \quad x^{2}+y^{2} \geq 1 \]

Plot the streamlines for \(\psi=0, \pm 60.0625\), and describe the physical situation represented by this equation. The parameter \(U\) is an upstream uniform velocity of \(1.0 \mathrm{ft} / \mathrm{s}\).