Problem 6.270

Protons with kinetic energy $T=1.0 \mathrm{MeV}$ striking a lithium target induce a nuclear reaction $p+\mathrm{Li}^{7} \rightarrow 2 \mathrm{He}^{4} .$ Find the kinetic energy of each alpha-particle and the angle of their divergence provided their motion directions are symmetrical with respect to that of incoming protons.