Isotope Carbon 14 (mass 2.34x10^ -26 kg)
In one such decay the electron and the neutrino are emitted at right angles to each other. The electron (mass 9.11x10^ -31 kg)has a speed of 3.8x10^ 7 m/s and the momentum of 7.6x10^ -24 kg m/s.
What is the recoil speed of the nucleus?