It’s a multiple choice and I think I have it, but I just want to make sure because we just scraped over the surface of gravitation.
I used conservation of mechanical energy where ΔU = -GMm/r and ΔK = (1/2)mv^2
Setting them equal and opposite, m cancels and we get:
v^2 = 2GM/r, where r is the radius of earth plus the altitude. I get that the answer is 1968 m/s. Am I doing this correct? I only ask because my answer would then be "None of these is correct" for the multiple choice.