Based on the calculations, the incident wave would be down to 1 mV/m at a depth of 287.82 meters.
Since the medium is a wet soil, it is characterized by the following:
Next, we would determine loss tangent, so as to know if the wet soil is a low-loss medium:
For a low-loss medium; ε''/ε' = σ/ωε < 0.01.
[tex]\frac{\sigma}{\omega \epsilon} = \frac{5 \times 10^{-4} \;\times\; 36 \pi}{2\pi \;\times \;3 \times 10^9\; \times\; 10^{-9} \times \;9} \\\\\frac{\sigma}{\omega \epsilon} =3.32 \times 10^{-4}[/tex]
Therefore, the wet soil medium is a low-loss dielectric and its absorption (attenuation) coefficient is calculated by using this formula:
Note:
[tex]\alpha = \frac{\sigma}{2}\sqrt{\frac{\mu}{\epsilon}} \\\\\alpha = \frac{\sigma}{2} \times \frac{120\pi}{\sqrt{\epsilon_r} } \\\\\alpha =\frac{5 \times 10^{-4} \times 120\pi}{2 \times \sqrt{9} } \\\\[/tex]
α = 0.032 Np/m.
Now, we calculate the depth:
[tex]E(z) = E_oe^{-\alpha z} = 10e^{-\alpha z}\\\\10^{-3}=10e^{-0.032 z}\\\\ln(10^{-4})=-0.032 z\\\\-9.21 \times 10^9=-0.032z\\\\z=\frac{-92.1 0}{-0.032}[/tex]
z = 287.82 meters.
Read more on low-loss dielectric here: https://brainly.com/question/14167707
