Any tips on how to do this?
A photon with wavelength 0.1395nm scatters from an electron that is initially at rest. What must be the angle between the direction of propagation of the incident and scattered photons if the speed of the electron immediately after the collision is 9.30×10^6m/s ?

Question

Any tips on how to do this? 
A photon with wavelength 0.1395nm scatters from an electron that is initially at rest. What must be the angle between the direction of propagation of the incident and scattered photons if the speed of the electron immediately after the collision is 9.30×10^6m/s ?

aaronq · Answer

You can start by find the energy of the electron $E_{photon}=\dfrac{hc}{\lambda}$

then use $KE=mv^2$ to find the energy necessary to accelerate the e to that speed

then i would use some trig

aaronq · Answer

i'm not sure if you have to use extended formulas because of the relativistic speeds though

ipwnbunnies · Answer

Use Compton Effect equation, mixed in with the conservation of linear momentum.

ipwnbunnies · Answer

Initial momentum is zero, since the electron is at rest.
So, the final momentum should be 0.
What I find strange is that they don't give the recoil angle for the electron.

ipwnbunnies · Answer

I guess it doesn't matter. Find the KE of the electron, find the energy of the photon. Should be equal to the energy of the incident photon. Then use the Compton Effect equation to figure out the angle the propagated photon has.