momentum and energy question
A nucleus, initially at rest, decays radioactively. In the process, it emits an electron horizontally to the east, with momentum 9.0 X 10–21 kg·m/s and a neutrino horizontally to the south, with momentum 4.8 X 10–21 kg·m/s.
(a) In what direction does the residual nucleus move?
(b) What is the magnitude of its momentum?
(c) If the mass of the residual nucleus is 3.6 X 10–25 kg, what is its recoil velocity?