Question

Find the maximum magnitude of the linear momentum of a photoelectron emitted when light of wavelength 400 nm falls on a metal having work function 2.5V

Answer 1

Kinetic Energy of the photoelectron emitted = 
 = h c/λ - 2.5V * e = 6.67*10⁻³⁴ * 3 *10⁸/400*10⁻⁹ - 2.5 * 1.6 *10⁻¹⁹  J
 = 1.0025 * 10⁻¹⁹J

KE = p * c
   =>  p = KE/ c = 1.0025 * 10⁻¹⁹ / 3*10⁸
            = 3.3416 * 10⁻²⁸ kg-m/sec