Question: start with the lienardwiechert potentials for a moving point chart...
Start with the Lienard-Wiechert potentials for a moving point chart A, φ and derive the electric and magnetic field for the charge:
Explicitly show what happens in the far-field approximation, when one can neglect terms of order of the square of the ratio of the source size divided by the distance to the field point (i.e. O|r'max|2/R2). Using this approximation, derive the Poynting flux for the EM field assuming one is far from the source, and can use the plane-wave approximation. Explicitly calculate the time average poynting flux. Use Gaussian units throughout.