The electric field of a plane wave propagating in a lossless, non-magnetic, dielectric material with a relative permittivity er=1 is given by: = 100 cos(4t10 t - kz)ux (v/m) [5 marks] q 3(a) determine the angular frequency, the frequency, the wave velocity, the wavelength and the wave vector (magnitude and direction). [10 marks] q 3(b) calculate the time domain expression for the magnetic field, h. [10 marks] q 3(c) give the time domain expression for the instantaneous poynting vector associated with this tem wave. [5 marks] q 3(d) what is the time average value of this poynting vector?