We have thus far discussed the properties of a fluid which is static – that is, no part of the fluid is in motion.  We have been introduced to the definitions of density and pressure associated with such a fluid, and have seen how pressure varies with depth beneath the surface of a static fluid. 

We will now discuss some fundamental properties of a fluid in motion, which will introduce us to the topic of fluid dynamics .  There are some strict constraints on the type of fluid flow we will consider – these constraints will be discussed in the first section of this lecture.  The remainder of the lecture will center on two  fundamental equations in fluid dynamics – the Equation of Continuity (or the Conservation of Mass), and Bernoulli’s equation. The discussions of these equations, sprinkled with a couple of examples, will complete this lecture.