Answer:
0.0018 W/m²
Explanation:
Power and intensity are related as:
[tex]I=\frac{P}{4\pi r^2}[/tex]
P= 20.0 W (given)
r = 30.0 m (given)
[tex]I=\frac{20.0}{4\pi(30.0)^2}=0.0018 W/m^2[/tex]
Intensity in decibels:
[tex]I(dB)=10log\frac{I}{I_o}\\=10log\frac{0.0018}{10^{-12}}=92.5 dB[/tex]
