Answer:
0.733 m
Explanation:
The maximum safe intensity for human exposure is
[tex]I= 1.48 W/m^2[/tex]
Intensity is defined as the ratio between the power P and the surface irradiated A:
[tex]I=\frac{P}{A}[/tex]
For a source emitting uniformly in all directions, the area is the surface of a sphere of radius r:
[tex]A=4 \pi r^2[/tex]
So
[tex]I=\frac{P}{4\pi r^2}[/tex]
In this case, we have a radar unit with a power of
P = 10.0 W
So we can solve the previous equation to find r, which is the distance at which a person could be considered to be safe:
[tex]r=\sqrt{\frac{P}{4\pi I}}=\sqrt{\frac{10.0 W}{4 \pi (1.48 W/m^2)}}=0.733 m[/tex]
