found as VPldisk = LB disk x r P. This sole rotating condition continues until the time t = i], when a harmonic wind eld with the velocity vector of Vwind = a2 cos z'i+ b2 cos x j+ c2 cos y k starts to blow over the rotating disk. The particle remains under the influence of the rotating disk and the blowing breeze with the velocity vector of VPldisk, wind until t = t2. At this time, a tornado with angular velocity of u? tomoado = a3x'i+ b3yj+ CSZk emerges over the rotating disk and becomes the third component for determining the velocity of the randomly located particle, i.e., VPldisk, wind, tornado. b. What is the curl of VPldisk,wind at the time t1 5 t