In this lesson, the concept of flux of a vector field across a curve is explored, with a focus on the interpretation of flux as a measure of how much fluid passes through the curve per unit time, counting positively what goes to the right and negatively what goes to the left. The computation of flux in coordinates is also introduced, providing a more practical way to calculate it when a geometric interpretation is not available. Examples are provided, including the flux of a vector field across a circle and how to handle a vector field that is tangent to the curve.
A lesson about flux and more on Green's Theorem.
Denis Auroux. 18.02 Multivariable Calculus, Fall 2007. (Massachusetts Institute of Technology: MIT OpenCourseWare). http://ocw.mit.edu (Accessed March 21, 2009). License: Creative Commons Attribution-Noncommercial-Share Alike.