Consider a two-dimensional flow which varies in time and is defined by the velocity field, u = 1 and v = 2yt. a) Is the flow field incompressible at all times? b) Compute the convective derivative of each velocity component: Du/Dt and Dv/Dt. c) By considering the velocity gradients, determine whether the fluid elements experience any deformation. What type(s) of deformation do they experience?