[填空题]
A negative muon traveling at 33% the:ebq;r kz:+xa zreud r;-; v-h speetc vfi9b33se4 gd z //tnlsu,.(jjg)ld of light collides head on with a positive muon traveling at 50% the speed of light. The two muons (ne/(.fd,l 3)l sgc 4vj/9z 3ubtsjgit each of rest mass $m_\mu = 105.7 \, \text{MeV}/c^2$) annihilate, and produce how much electromagnetic energy?E = MeV
