Annihilation occurs between an electron and positron at rest, producing three photons. Calculate the energy of the third photon of the energies if the two of the photons are 0.20 MeV and 0.30 MeV. Identify how many positrons can a 200 MeV photon produce?​

moving ball hits still ball. mover stops, hit ball moves. momentum transfer.

probably not if net force is zero

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)