The velocity field of a fluid is given by F(x, y, z) = 5z k and let S be a sphere x² + y2 + z² = 16x Calculate the flux of F through S. 2. If F(x, y, z) = x²yi + y²j+xz k and S is the cube of the first octant limited by the planes x = 1; y=1 and z = 1 and the coordinate planes. Calculate the flux of F through S.