Problem 4: Although electromagnetic waves can always be represented as either ph
ID: 3308771 • Letter: P
Question
Problem 4: Although electromagnetic waves can always be represented as either photons or waves, in the radio part of the spectrum we typically do not discuss photons (like we do in the visible) because they are at such a low energy. Nevertheless, they exist. Consider such a photon in a radio wave from an AM station has a 745 kHz broadcast frequency. Part (a) What is the energy, in joules, of the photon? Numeric A numeric value is expected and not an expression. E= Part (b) What is the energy, in electron volts, of the photon? Numeric A numeric value is expected and not an expression.Explanation / Answer
a) Energy = hf
where h = planck's constant
f = frequency
= 6.626*10^-34*1745000
= 1.15*10^-27 J
b) energy in eV = 1.15*10^-27 / (1.6*10^-19) = 7.22*10^-9 eV