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samuelyee
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Homework Statement
A photon of energy E is scattered off a stationary electron with rest mass m. What is the maximum kinetic energy of the recoiling electron?
Homework Equations
[tex]\lambda'-\lambda=\frac{h}{mc}(1-cos(\phi))[/tex]
[tex]E=\frac{hc}{\lambda}[/tex]
The Attempt at a Solution
The maximum kinetic energy gained is when [tex]\phi=180^{o}[/tex] , so
[tex]\lambda'-\lambda=\frac{2h}{mc}[/tex]
After some manipulation, I finally get
[tex]K = \frac{2E^2}{2E+mc^2}[/tex]
But the answer is supposed to be [tex]K = \frac{E^2}{E+mc^2}[/tex] , which would be the case if the cosine term is zero. Am I making the wrong assumption at the start?
Thanks for the help!
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