(a) If the power output of a 670 kHz radio station is 49.0 kW, how many photons per second are produced? 1.1679e32 X How does power relate to energy? Review the relationship between energy and frequency of a photon. 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 125 km. Assume no reflection from the ground or absorption by the air. 2.138e21 If there is no reflection by the ground, what fraction of the radiated power reaches the receiver? What portion of the spherical surface do you need to consider here? photons/(s · m2)

(a) If the power output of a 670 kHz radio station is 49.0 kW, how many photons per second are produced? 1.1679e32 X How does power relate to energy? Review the relationship between energy and frequency of a photon. 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 125 km. Assume no reflection from the ground or absorption by the air. 2.138e21 If there is no reflection by the ground, what fraction of the radiated power reaches the receiver? What portion of the spherical surface do you need to consider here? photons/(s · m2)