## College Physics (4th Edition)

(a) The wave is traveling in the -z-direction. (b) We can write the components of the electric field of this wave: $E_x = -(c~B_m)~cos~(kz+\omega~t)$ $E_y = 0$ $E_z = 0$
(a) From the term $kz+\omega~t$, we can see that the wave is traveling in the -z-direction. (b) Since the direction of propagation is determined by the cross-product $E\times B$, by the right-hand rule, the electric field must be pointing in the -x-direction at z = 0 and t = 0. Note that $(-x)\times (+y) = -z$ We can write the components of the electric field of this wave: $E_x = -(c~B_m)~cos~(kz+\omega~t)$ $E_y = 0$ $E_z = 0$