Which electron on annihilation will release more energy

[sharma_satdev]

Homework Statement

which electron on annihilation will release more energy ,the one at rest or the one in relative motion

Homework Equations

The Attempt at a Solution

 

[ideasrule]

Where's your attempt? Remember that the annihilation involves, in the reference frame of the two particles' center of mass, the particles rushing in at each other at the same speed and two photons going out in the opposite direction.