A plane electromagnetic wave E = Em cos (wt kr), where Em = Emey, k =

Question:

A plane electromagnetic wave E = Em cos (wt – kr), where Em = Emey, k = kex, ex, ey are the unit vectors of the x, y axes, propagates in vacuum. Find the vector H at the point with radius vector r = xex at the moment
(a) t = 0,
(b) t = to. Consider the case when Em = 160 V/m, k ----- 0.51 m-1, x = 7.7 m, and to = 33 ns.