When a Metal Surface Is Illuminated with Light of Wavelength

question 3

Essay

When a metal surface is illuminated with light of wavelength 437 nm,the stopping potential for photoelectrons is 1.67 V.(c = 3.00 × 10⁸ m/s,h = 6.626 × 10^-34 J ∙ s,e = -1.60 × 10^-19 C,
1 eV = 1.60 × 10^-19 J,m_el = 9.11 × 10^-31 kg)
(a)What is the work function of the metal,in eV?
(b)What is the maximum speed of the ejected electrons?