The work function for tungsten is = 4:6eV . (a) If light is incident on tungsten, what’s the critical frequency f0, below which no elections will be

The work function for tungsten is φ = 4:6eV . (a) If light is incident on
tungsten, what’s the critical frequency f0, below which no elections will be
ejected. What is the corresponding wavelength λ0? Find the maximum kinetic
energy of an emitted electron if tungsten is irradiated with light with (b) λ =
200nm or (c) λ = 300nm. Explain your answer to (c).