An elcetron and a positron moving at small speeds collide and annihilate each other. Find the energy of the resulting gamma photon .

Explanation

Mass of Electron = Mass of positron
` = 9.1 xx 10^(-31) kg `
Both are oppositely charged and they annihialte each other .
Hence ` Delta m = m + m `
` = 2 xx 9.1 xx 10^(-31) kg `
Energy of the resulting ` gamma ` particle
` Delat m C^(2)`
2 xx 9.1 xx 10^(-31) xx 9 xx 10^(16) J`
` = 2 xx 9.1 xx 9 xx 10^(-15) / 1.6 xx 10^(-19)
` = 102 . 37 xx 10^(4) eV `
` = 1.02 xx 10^(5)eV`
` = 1.02 MeV` .