The velocity profile for steady flow between parallel is parabolic and given by \(u=u_{c}+a y^{2}\), where \(u_{c}\) is the centerline velocity and \(y\) is the distance measured from the centerline. The plate spacing is \(2 b\) and the velocity is zero at each plate. Demonstrate that the flow is rotational. Explain why your answer is correct even though the fluid doesn't rotate but moves in straight parallel paths.