Question

A metal surface has a work function of 4.85eV. Calculate the maximum kinetic energy in joules of the electrons emitted when the metal is irradiated with uv light of frequency 1.75×1015Hz.

Answer 1

E = hf
hf = θ+K.E max.
6.0×10^-34×1.75×10¹⁵
= 2.4×10^-19+K.E max
K.E max = (6.0×10^-34×1.75×10¹⁵ )- 2.0×10^-19
= 2.74×10^-19J