Just like with other mechanical systems, we can work both of our two major problems for the course with fluids. Adding the buoyant force gives us a way to work Newton’s Second Law problems with a static fluid. Keeping track of the terms in Bernoulli’s equation is working a conservation of energy density problem for a fluid that flows between two points. In either case, our model for a fluid allows us to connect substances that seem very different from the other objects we have studied to the two key concept of the course.