De broglie wavelength

Hi ariana13 and welcome to PF,

I'm assuming that this is a homework question, in which case for future reference we have Homework & Coursework problems for such questions. Don't worry about it now, your thread will get moved there in due course.

Now for your question. What do you know about the de Broglie wavelength? How is it claculated?

 

Since we are taking about energies here, it may be more useful to use an alternative form for the de Broglie wavelength for the electron,

[tex]\lambda = \frac{hc}{pc} = \frac{hc}{\sqrt{T^2+2Tm_0c^2}}[/tex]

 

There are no stupid questions

Anyway, it comes from the relativistic energy eqaution,

[tex]E^2 = \left(pc\right)^2 + \left(m_0c^2\right)^2[/tex]

Where E it the total energy. In the expression in my previous post T represents the kinetic energy of the electron. Of course if one would prever to calculate the total energy of the electron (including rest energy) one may rewrite the previous equation,

[tex]\lambda = \frac{hc}{pc} = \frac{hc}{\sqrt{E^2 - m_0^2c^4}}[/tex]