A uranium-238 atom can break up into a thorium-234 atom and a particle called an alpha particle, α-4. The numbers indicate the inertias of the atoms and the alpha particle in atomic mass units (1 amu = 1.66 × 10−27 kg). When an uranium atom initially at rest breaks up, the thorium atom is observed to recoil with an x component of velocity of -2.6 × 105 m/s. How much of the Uranium atom's internal energy is released in the breakup? I know that this is an explosive separation problem and that the initial velocities are zero but I'm confused on how to approach this problem.