The photoelectric effect is studied using a tungsten target. The work function of tungsten is 4.5 eV.

Question:

The photoelectric effect is studied using a tungsten target. The work function of tungsten is 4.5 eV. The incident photons have energy 4.8 eV.
(a) What is the threshold frequency?
(b) What is the stopping potential?
(c) Explain why, in classical physics, no threshold frequency is expected.