Calculating Energy of Radiation in Proton-Antiproton Annihilation

[ProPatto16]

Homework Statement

in proton-antiproton annihilation a proton and an antiproton collide and disappear producing electromagnetiv radiation. if each particle has a mass of 1.67*10^-27 and they are at rest just before collision, find total energy of radiation and give answer in joules and electron volts.

Homework Equations

rest energy, E=mc²

The Attempt at a Solution

E = [1.67*10^-27 x (2.998*10⁸)²] x 2

= 3.002*10^-10 J

= 1.87GeV

is that right? the question is for 10 marks and it just seems to easy??

 

[Mr.A.Gibson]

Your method is correct as far as I can tell. Two photons would have to be produced to conserve momentum but the question does ask for the total energy.

Perhaps the number of marks is a misprint.