What is the energy loss of a solid sphere hitting a wall obliquely?

  • Level: Graduate 
  • Thread starter Thread starter physmurf
  • Start date Start date
  • Tags Tags
    Energy Momentum
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
2 replies · 2K views
physmurf
Messages
26
Reaction score
0
So, I am reading about a compton scattering problem, and I don't understand part of the derivation of a formula. I will explain my confusion.

If a gamma photon with energy [tex]E_{\gamma}[/tex], undergoes compton scattering with an electron which is at rest, how does one arrive at the following expression?

[tex]E^{'}_{\gamma}=\frac{E_{\gamma}}{1+(2E_{\gamma}/m_{o}c^{2})}[/tex]

So far it says we start with the conservation of energy and momentum:
[tex]E_{\gamma}=E^{'}_{\gamma}+E_{e} \ \ (eqn 1)[/tex]
[tex]\frac{E_{\gamma}}c=P_{e}-\frac{E^{'}_{\gamma}}{c}\ \ (eqn 2)[/tex]

From eqn 2 we get:
[tex]E_{\gamma}+E^{'}_{\gamma}=p_{e}c=\sqrt{(E_{e}+m_{o}c^{2})^{2}-(m_{o}c^{2})^{2}}[/tex]

This is where I am confused. I don't understand where the term inside of the radical comes from. Any ideas?
 
Physics news on Phys.org
physmurf said:
[tex]E_{\gamma}+E^{'}_{\gamma}=p_{e}c=\sqrt{(E_{e}+m_{o}c^{2})^{2}-(m_{o}c^{2})^{2}}[/tex]

The [itex]E_e[/itex] in the square root on the right is the electron's kinetic energy, which most books call [itex]K_e[/itex]. [itex]E_e[/itex] usually means the total energy:

[tex]E_e = K_e + m_0 c^2[/tex]

Using this notation, the relationship between energy, momentum and mass is

[tex]E^2 = (pc)^2 + (m_0 c^2)^2[/tex]

so

[tex]p_e c = \sqrt {E_e^2 - (m_0 c^2)^2} = \sqrt {(K_e + m_0 c^2)^2 - (m_0 c^2)^2}[/tex]
 
Last edited:
hi all,

a similar post for me. pls help me.
i need to calculate the energy lost by a solid sphere (~ 0.5 mm dia) on hitting the solid wall obliquely.
i know the tangetial and normal velocities and the restitution coefficients. what other parameters do i need to know ??

help with the expression or a reference to articles in the web would be of great help.

thanks you.