1. The problem statement, all variables and given/known data 2. Relevant equations energy conservation 3. The attempt at a solution I used this equation: 1/2 mg R^2/ r1 + 1/2 mv1^2 = 1/2 mg R^2/ r2 + 1/2 mv2^2 For r1, it is 1738 km (radius) + 1000 km (above surface) ? But for r2 , it is on the surface, so would it be 0??