Let x, y, and z be measured in meters, and suppose that F(x, y, z) = yi + zj + 3xk is the velocity vector of a fluid particle at the point (x, y, z) in a steady-state incompressible fluid flow. a) Find the net volume of fluid that passes in the upward direction through the hemisphere z = 9-x - y in one second. b) Assuming that the fluid has a mass density of 1060 kg/m, find the net mass of fluid that passes in the upward direction through the surface in part (a) in one second.