A ground penetration radar sends a plane wave with electric field E_{r,t}=15e^{-az}cos(22.5 imes 10t+z) through dry soil, with mu_{r}=1, epsilon_{r}=3.5, and sigma=0.01 S/m. The wave penetrates the ground (z=0) and hits a metallic plate at 10 meters below ground.
(a) Is the dry soil a good dielectric, a good conductor, or neither?
(b) What is the propagation constant of soil?
(c) Write the magnetic field phasor of the plane wave. What is the phase difference between the electric and magnetic field?
(d) The metallic wave perfectly reflects the wave back towards ground. What is the amplitude of the electric field of the plane wave when it gets reflected back to ground level?