During a classroom discussion a teacher states, “Light slows down in water because…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
During a classroom discussion a teacher states, “Light slows down in water because each photon loses energy as it enters the water.” Evaluate the validity of this statement.
(a) Using appropriate physical principles, explain whether the energy of an individual photon changes when it passes from air into water.
(b) Identify which physical properties of the photon do change upon entering the water and provide a reasoned explanation for those changes.
(c) Describe one experimental observation, such as from the photoelectric effect or another modern-physics experiment, that supports your conclusions in parts (a) and (b).