The electric and magnetic fields at t=0 are:
E = Eâ‚€(z)x and B = Bâ‚€f(z)y
with f(z) = exp(-az²)
a) Find the electromagnetic energy and momentum density and their ratio.
b) Show that at t>0 there are two wave packets traveling in the directions ±2.
c) At what ratio E/Bâ‚€ do we have only one wave packet?
d) How much of the initial energy is carried in the ±2 directions?