7) A force with unit in Newton and defined by f = [300, 700, 500] acts on an object with displacement, in meters, defined by d = [3, 1, 12]. [A] a) Determine the work down in the direction of travel. b) Determine the work down against gravity, which is a force in the direction of the negative Z- axis. 8) Determine the projection, and its magnitude, of u = [-2, 5, 3] on v = [4, -8, 9]. [K]