Problem 6.269

An alpha particle with kinetic energy \(T=5.3 \mathrm{MeV}\) initiates a nuclear reaction \(\mathrm{Be}^{9}(\alpha, n) \mathrm{C}^{12}\) with energy yield \(Q=\) \(=+5.7 \mathrm{MeV}\). Find the kinetic energy of the neutron outgoing at right angles to the motion direction of the alpha-particle.