1. The problem statement, all variables and given/known data Determine the Strain Rate for a Material Fiber in the direction of the surface normal. The Velocity Field is V=((4y-3x)i+(5x+3y)j) ft/s http://puu.sh/9hQ7Q/2bda80620f.jpg [Broken] is the picture which describes a steady, planar flow where i and j are unit vectors. 2. Relevant equations n * (n * ∇) V where n is the unit normal, and * are dot products. 3. The attempt at a solution I know that the solution to this itself is very simple, it is just math, my biggest issue though is how do I find the unit normal vector? I have no idea where to begin, any hints would be greatly appreciated!