Problem 15. Find the surface area of the part of the cone- that lies below the plane z + 2z 3. Problem 16. Calculate the charge of a part of the saddle surface 2z = 2.2-y2 that lies inside the cylinder y f the charge density at each point (, y, 2) on the surface is @ã¶+1 Surface integrals of a vector field Problem 17. Let V be the solid cylinder Find the flux of F = (x, y, z) outward the boundary of V in two ways: by the definition of flux and using the divergence theorem.