In unit-vector notation, what is the torque about the origin on a particle located at coordinates (0, -4.90 m, 4.04 m) due to (a) force 1 with components F1x = 2.67 N and F1y = F1z = 0, and (b) force 2 with components F2x = 0, F2y = 1.23 N, F2z = 5.41 N?