Let t be the tetrahedron with vertices at the origin and (6,0,0), (0,2,0) and (0,0,4). a fluid flows with velocity ⟨ x e y , y , − z e y ⟩ , where position is measured in meters, and speed is measured in meters per second. find the rate of flow outward through the slant surface of the tetrahedron, which is the only face that is not parallel to any of the coordinate planes.