## Questions 22-23 An electron and a positron

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

## Questions 22-23 An electron and a positron, each of mass

9.1 \times 10^{-31}

kilogram, are in the same general vicinity and have very small initial speeds. They then annihilate each other, producing two photons. (A)

0^{\circ}

(B)

45^{\circ}

(C)

90^{\circ}

(D)

180^{\circ}