(a) If the power output of a 630 kHz radio station is 50.0 kW, how many photons per second are produced?
-------------- photons/s
(b) If the radio waves are broadcast uniformly in all directions, find the number of photons per second per square meter at a distance of 100 km. Assume no reflection from the ground or absorption by the air.
-------------- photons/s·m2