So, these are components wise if these three quantity is as 0 for a particular velocity vector q bar, our q bar is the velocity vector omega bar is the angler velocity. And what we call the vorticity vector, then if omega bar is 0, than this 3 quantities are 0 and we say the flow as irrotational flow is irrotational or we sometimes we call is at vortex free motion.
(Refer Slide Time: 33:15)