A flow can be visualized by plotting the velocity field as velocity vectors at represent...

A flow can be visualized by plotting the velocity field as velocity vectors at representative locations in the flow as shown in Video V4.2 and Fig. E4.1. Consider the velocity field given in polar coordinates by v_r= -10/r and v_θ = 10/r. This flow approximates a fluid swirling into a sink as shown in Fig. P4.4. Plot the velocity field at locations given by r = 1, 2, and 3 with θ = 0, 30, 60, and 90°.