Wavelength from collision

[Damascus Road]

Hey all,

A physics example I'm working on to do some studying. The example is as follows:

What is the wavelength of the scattered photon when a free electron (initially stationary) acquires maximum energy in a collision with a photon of energy 4 x 10^3 eV?

My problem is this: it seems anything I do only deals with the photon of energy 4 x 10^3 eV. i.e. I can find the frequency using the relation E=hf and then lambda using lambda = c/f, but none of that relates to " lambda prime". Help?

Thanks in advance.

[Damascus Road]

to add... I have a feeling that the electron acquires "maximum energy" means something, that I am not picking up...

[jtbell]

This looks like a Compton scattering problem. Hint: In a collision that delivers the maximum possible KE to the electron, in what direction would you expect the photon to emerge (and which direction does the electron recoil)?

[Damascus Road]

got it, thanks!