When a metal surface is illuminated with light of wavelength 437 ...

[hubes95]

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, mel = 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?

Question 2

A 406.0 kg copper bar is put into a smelter for melting. The initial temperature of the copper is 300.0 K.
 
  How much heat must the smelter produce to completely melt the copper bar? (The specific heat for copper is 386 J/kgK, the heat of fusion for copper is 205 kJ/kg, and its melting point is 1357 K.)
  A) 1.66  1011 kJ B) 2.96  105 kJ C) 2.49  105 kJ D) 1.66  108 kJ

[TheDev123]

Answer to Question 1

(a) 1.17 eV (b) 7.66  105 m/s

Answer to Question 2

C

[hubes95]

Gracias!

[ecabral0]

Excellent