The magnetic field of a plane harmonic electromagnetic wave traveling in vacuum is given by: B (z, 1) = (28 uT) cos(kz-cut) ) with k = 50 m-1. Find: a. The direction of propagation. (You must explain your reasoning ) [3 points] b. The direction of polarization of this wave. (You must explain your reasoning.) [4 points] c. The intensity of the wave. [3 points]