A 500-kHz uniform plane wave propagates beneath the earth's surface. The amplitude of the - E field just beneath the surface is 120 V/m. If the relative permeability, the dielectric constant, and the conductivity of the earth are taken as 1, 16, and 0.02 S/m, respectively, determine (a) the propagation, attenuation, and phase constants, (b) the phase velocity, (c) the wavelength, (d) the intrinsic impedance, (e) the skin depth, and (f) the average power density. If the range is considered to be the distance at which 90% of the wave is attenuated, find the range of the signal being transmitted.