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Einstein's photoelectric equation

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Problem

When light photons having energy E=2.96 eV strike a ceasium surface, the most energetic electrons have kinetic energy 0.80 eV.
Find the minimum frequency of light for which photoelectric emission takes place from the caesium surface. Note: Take h=6.63×1034 J s and e=1.60×1019 C and round-off your answer to three significant figures.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
×1014 Hz