Answer:
[tex]I_{300} =2777.7uW/m^{2}[/tex]
Explanation:
Looking at the formula of intensity we can see that it is inversely proportional to the square of distance and the other terms are all constant
So
[tex]I=\frac{P}{A}\\I=\frac{P}{\pi d^{2} }\\I=C\frac{1}{d^{2} }[/tex]
We can now write the following equality
[tex]\frac{I_{300} }{I_{50}}=\frac{50^{2} }{300^{2} }\\ I_{300} =\frac{50^{2} }{300^{2} }*I_{50}\\I_{300} =0.02777*I_{50}[/tex]
Substitute the know intensity at 50m we get
[tex]I_{300} =0.02777(0.1W/m^{2} )\\I_{300} =2777.7uW/m^{2}[/tex]
