Consider a two-dimensional, incompressible flow field in which an initially square fluid particle moves and deforms. The

Question:

Consider a two-dimensional, incompressible flow field in which an initially square fluid particle moves and deforms. The fluid particle dimension is a at time t and is aligned with the x- and y-axes as sketched in Fig. P4–76. At some later time, the particle is still aligned with the x- and y-axes, but has deformed into a rectangle of horizontal length 2a. What is the vertical length of the rectangular fluid particle at this later time?

FIGURE P4–76