An unstable nucleus initially at rest undergoes spontaneous binary fission, splitting into two fragments of masses \(m_1\) and \(m_2\). The total mass of the initial nucleus exceeds the combined mass of the fragments, resulting in a release of energy \(Q\) that is converted entirely into the non-relativistic kinetic energies of the two fragments. What is the kinetic energy \(K_1\) of the fragment of mass \(m_1\) in terms of \(m_1\), \(m_2\), and \(Q\)?