2. A stationary particle having a rest mass energy of 1400 MeV disintegrates into two particles called \"pions,\" a 3+ and a :r, that travel in opposite directions, as shown schematically in Fig. 124. Each of the pions has a restmass energy of 140 MeV. a -. a 5.5;; ' a 3. Find the kinetic energy, in appropriate units, of each outgoing particle. b. What is the value of y (\"gamma\"} for either pion'? c. When the pions are at rest, they have a lifetime of 0.28 ns. According to an observer in the laboratory, what is the lifetime of the moving pions (in us)