Question

Consider a velocity field $\vec{V}=K\left ( y\hat{i}+x\hat{k} \right ),$  , where K is a constant. The vorticity, $\Omega _{z}$, is                                                                            

      (a) –K                                                                 (b) K

      (c) –K/2                                                              (d) K / 2