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babypudding
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Maximum work function??
What is the maximum work function for a surface to emit electrons when illuminated with 900nm infrared light?
K= 1/2mv2
= hf - work function
wavelength =h/p = h/mv
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.
Homework Statement
What is the maximum work function for a surface to emit electrons when illuminated with 900nm infrared light?
Homework Equations
K= 1/2mv2
= hf - work function
wavelength =h/p = h/mv
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.