Hello all, I have a problem with a typical style of problem I seem to always struggle with. Just to clear this up, I am studying for my comprehensive exams later this summer. So I am going through past problems to bone up on the last two years of grad school. At which point I came across this type of problem that I see to always struggle with so I am here to gain some insight on how to do these problems and what is being asked of me. The question goes as such: "Qualitatively estimate the frequency and power of electromagnetic radiation emitted by a cellular phone during a typical phone call." Now there are a few things I know and a few things that are given on the exam: I know P(r)=I(4πr2) and I=1/2ε0cE2 I am also given the equation for the "Time averaged power radiated per unit solid angle" (See Jackson eqn 9.56) with Z0=377Ω Now I have given you everything I have been given, so my question stands. Obviously there should be enough info here seeing as this is a past comprehensive exam, but I don't have the foggiest idea how to start. I strongly feel like I don't have enough info to go forward with, but I know I am wrong. Any insight or advice is strongly appreciated.