Photoelectric effect: maximum kinetic energy
Photons of 6.0 eV strike a metal with a work function of 4.5 eV. What is the maximum kinetic energy of the ejected electrons?
Answer A: explanation for every choice
A
Correct. KEmax = hf − Φ = 6.0 − 4.5 = 1.5 eV.
B
4.5 eV is the work function, the energy needed just to free an electron.
C
This ignores the work function.
D
This adds the work function instead of subtracting it.
TakeawayKEmax = hf − Φ.
Equation usedPhotoelectric effect
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