Assignment:
A nucleus of helium with mass 5 amu breaks up from rest into a nucleus of ordinary helium (mass = 4 amu) plus a neutron (mass = 1 amu). The energy liberated in the break-up is 0.89 MeV, which is shared (not equally) by the products in the form of kinetic energy.
a) Using the conservation of momentum find the kinetic energy of the neutron.
b) The lifetime of the original nucleus is 1.0E-21 s. Because we are not sure when during this lifetime this reaction will occur (i.e., decay), the uncertainty of the time is equal to the lifetime. What range of values of the neutron kinetic energy might we measure in the laboratory as a result of the uncertainty relationship?