1. The problem statement, all variables and given/known data Given: G = 6.67259 × 10^−11 Nm2/kg2 Two hypothetical planets of masses 2.5 × 10^23 kg and 7.8×10^23 kg and radii 3.2×10^6 m and 7.1×10^6 m, respectively, are at rest when they are an infinite distance apart. Because of their gravitational attraction, they head toward each other on a collision course. When their center-to-center separation is 4.5 × 10^8 m, find their relative velocity. An- swer in units of m/s. 2. Relevant equations 3. The attempt at a solution F=GMm/r^2 M=7.8e23 kg m=2.5e23 kg Ki+Ui=Kf+Uf r=4.5e8+3.2e6 +7.1e6=460300000m 0+0=.5mv^2+(-GMm/r) .5v^2=GM/r v=475.54 m/s Is this answer correct?