Q. Particle A and particle B are held together with a compressed spring between them. When they are free, the spring pushes them apart and they after that fly off in opposite directions, free of the spring. The mass of A is 3 times the mass of B, and the energy stored in the spring was 45 J. Suppose that the spring has negligible mass and that all its stored energy is transferred to the particles. Once that transfer is complete, what are the kinetic energies of (a) particle A and (b) particle B?