As we learned in Section 3.9, an electron and positron can annihilate each other complet...

As we learned in Section 3.9, an electron and positron can annihilate each other completely and form two gamma rays. (a) If the electron and positron were initially at rest, what are the wavelengths of the two emitted gamma rays? (b) Repeat if the electron and positron were each traveling at a speed of 0.30c measured in the lab and collided head-on.