Maximum work function?? 1. The problem statement, all variables and given/known data What is the maximum work function for a surface to emit electrons when illuminated with 900nm infrared light? 2. Relevant equations K= 1/2mv2 = hf - work function wavelength =h/p = h/mv 3. The attempt at a solution p=h/wavelength = 6.626 x 10-34 / 900 x 10-9 = 7.362 x 10-28 kgm/s p=mv v=p/m =7.362 x 10-28 / 9.11x10-31 = 1027.66 m/s K=1/2mv2 =1/2 x 9.11x10-31 x 1027.662 =4.81x10-25 J frequency x wavelength = c (no sure if this is right, where c is the speed of light) f= 3x108/ 900 x 10-9 =270 work function= hf- K = 6.626 x 10-34 x 270 - 4.81x10-25 = -4.81J My answer looks wrong, so I think I did it wrong. Please lead me to the right direction.