A Fluid flow is given by  

\(V = \left( {2x + \frac{{{y^3}}}{3} - {x^2}y} \right)\hat i + \left( {x{y^2} - \frac{{{x^3}}}{3} - 2y} \right)\hat j\)

Check whether the given flow is possible case of fluid flow or not. If possible, determine angular velocity about z-axis.