When a Photoelectric Surface Is Illuminated with Light of Wavelength $437 \mathrm {~nm}$

When a photoelectric surface is illuminated with light of wavelength $437 \mathrm {~nm}$ , the stopping potential is measured to be $1.67 \mathrm {~V} . \left( 1 \mathrm { eV } = 1.60 \times 10 ^ { - 19 } \mathrm {~J} , e = 1.60 \times 10 ^ { - 19 } \mathrm { C } , m _ { \mathrm { e } } \right.$ ectron = $\left. 9.11 \times 10 ^ { - 31 } \mathrm {~kg} , h = 6.626 \times 10 ^ { - 34 } \mathrm {~J} \cdot \mathrm { s } \right)$
(a) What is the work function of the metal, in $\mathrm { eV }$ ?
(b) What is the maximum speed of the ejected electrons?