Physics

Problem

A research setup requires photoelectrons to emerge with speeds of at least

8.0 \times 10^{5}\,\text{m/s}

from a metal whose work function is

2.4\,\text{eV}

. Which of the following laser wavelengths will satisfy this requirement? a)

520\,\text{nm}

690\,\text{nm}

250\,\text{nm}

350\,\text{nm}