Fluids in Motion Up to now we have described fluids in terms of their static properties density p pressure p To describe fluid motion, we need something that can describe flow velocity v There are different kinds of fiuid flow of varying complexity non-steady / steady compressible incompressible rotational irrotational VISCOUS idea Physics 121: Lecture 21, PgPhysics 121: Lecture 21, Pg 4 Fluids in Motion Up to now we have described fluids in terms of their static properties: density  pressure p To describe fluid motion, we need something that can describe flow: velocity v There are different kinds of fluid flow of varying complexity non-steady / steady compressible / incompressible rotational / irrotational viscous / ideal