(adsbygoogle = window.adsbygoogle || []).push({}); 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= 1/2mv^{2}

= 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=1/2mv^{2}

=1/2 x 9.11x10^{-31}x 1027.66^{2}

=4.81x10^{-25}J

frequency x wavelength = c (no sure if this is right, where c is the speed of light)

f= 3x10^{8}/ 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.

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# Homework Help: Maximum work function?

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