Problem 5
Two radio-wave sources, which you may consider to be point-like,
are sitting a distance $L = 10.0$ m apart on the ground, as in the
image (top down view). Source 2 is on the end of a sidewalk that is
perpendicular to an imaginary line connecting the two sources. By
turning a knob, the controller can turn on source 1, source 2, or
both sources together. The sources always emit one single
frequency. When both sources are turned on together, the waves
they produce are in phase. The speed of radio waves is $c$, the speed of light.
A. Sources 1 and 2 are turned on, and emit radio waves of frequency $f = 100$ MHz. Suppose you want to
place your radio on the sidewalk. How far from source 2 should you position your radio so as to get the
"cleanest" reception (meaning the largest intensity)? You cannot just place the radio right next to source
2.
B. Now a radio-wave detector is placed midway between the two sources. When source 2 alone is turned
on, the intensity of waves at the detector is measured to be $I_o$. If both sources are turned on at once,
what will be the intensity at that detector? Express your answer in terms of $I_o$.
