In an experiment on an unknown photoemissive metal, monochromatic light of wavelength 400nm is directed onto the metal surface in vacuum. A potential difference is applied such that the collector plate is negative relative to the emitter. When the potential difference reaches −1.10V (collector negative), the photocurrent falls to zero.
(a) Determine the maximum kinetic energy, in electron-volts, of the emitted electrons.
(b) Using the constants provided below, calculate the work function of the metal in electron-volts.
$\begin{aligned}
c &= 3.00\times10^{8}\,\text{m}\,\text{s}^{-1}
h &= 6.63\times10^{-34}\,\text{J}\,\text{s}
e &= 1.60\times10^{-19}\,\text{C}
\end{aligned}$