A pion at rest (m = 273me) decays to a muon (m 207me) and an antineutrino. The

Question:

A pion at rest (mπ = 273me) decays to a muon (mμ ≈ 207me) and an antineutrino. The reaction is written π− → μ− + v. Find the kinetic energy of the muon and the energy of the antineutrino in electron volts. (Suggestion: Conserve both energy and momentum.)