A comet fragment of mass 1.96 × 1013 kg is moving at 6.50 × 104 m/s when it crashes into Callisto, a moon of Jupiter. The mass o
f Callisto is 1.08 × 1023 kg. The collision is completely inelastic. Assuming for this calculation that Callisto's initial momentum is zero kg · m/s, what is the recoil speed of Callisto immediately after the collision?