- #1
vsage
I have the formula for the de Broglie wavelength but for some reason I'm not using it properly. Here's the question:
What is the De Broglie wavelength (in nm) of a proton with a kinetic energy of 10 eV? (Take the mass of a proton to be 938 MeV/c2.)
\lambda = \frac{hc}{pc}
hc = 1239.8 nm*eV
pc = \sqrt{{KE}^2 + 2KEm_0c^2} which should be around 101.5 eV, so the answer would be 12.2nm which is wrong! What did I do wrong? It should have been a simple plug and chug problem after deriving pc in terms of KE and the rest mass.
What is the De Broglie wavelength (in nm) of a proton with a kinetic energy of 10 eV? (Take the mass of a proton to be 938 MeV/c2.)
\lambda = \frac{hc}{pc}
hc = 1239.8 nm*eV
pc = \sqrt{{KE}^2 + 2KEm_0c^2} which should be around 101.5 eV, so the answer would be 12.2nm which is wrong! What did I do wrong? It should have been a simple plug and chug problem after deriving pc in terms of KE and the rest mass.
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