) A neutral pion with rest mass 135MeV /c2 is traveling with speed 0.5c as measured in a lab. The pion then decays into two photons, one moving in the same direction as the original motion of the pion and the other moves in the opposite direction with energy 39MeV , as measured in the lab frame. (a) What is the energy and wavelength of the photon that moves in the same direction as the pion
