Phototherapy devices used in dermatology emit electromagnetic radiation of various wavelengths to treat skin disorders. In a simplified model, assume that the radiation travels through air at essentially the same speed as it would in a vacuum.
Answer the following questions. Use clear, well-reasoned explanations that incorporate relevant physical principles. No numerical calculations are required.
(a) Describe how the frequency of electromagnetic radiation changes when its wavelength decreases, and explain the physical basis for this relationship.
(b) Explain the connection between the energy carried by a single photon and the photon's wavelength.
(c) Suppose photon A has twice the wavelength of photon B. Compare the energies of photons A and B and justify your answer qualitatively.