A flow in the narrow gap between large parallel plates is shown. The velocity field in the narrow gap is given by \[\mathbf{V} = \frac{U}{h} y \hat{i}\]
where \(U = 4\) mm/s and \(h = 4\) mm. At \(t = 0\) line segments $ac$ and $bd$ are marked in the fluid to form a cross as shown.
(1) Evaluate the positions of the marked points at $t = 1.5$ s and sketch for comparison using appropriate software.
(2) Calculate the rate of angular deformation and the rate of rotation of a fluid particle in this velocity field. Comment on your results.