1. The problem statement, all variables and given/known data At a distance of 25m from an isotropic 100 MHz radio source the intensity is 120W/m2. A) What is the rms electric field at 25m? The answer should be 213 V/m. B) Over a 2 hour period, what is the momentum given to a 4cm x 4cm surface (at the 25m distance) perpendicular to the source that reflects 3/4 of the energy? The answer should be 8.06*10^-6. C) What is the total power transmitted by the source? The answer should be 9.42*10^5. 2. Relevant equations I=P/a = E^2max/2(u)(c) 3. The attempt at a solution Emax = 274587.4 Erms=Emax/sqrt(2) I can not get any of these parts right. I tried them but can't get the same results. Can someone show me how to get these? Thanks for the help!