mg = GmM/R^2 g = GM/R^2 g = Gρ*4πR^3/3 / R^2 = 4πGρR/3 对于“某星球”,同样地,g' = 4πGρ'R'/3 g' = g,ρ' = 2ρ,所以 g = 8πGρR'/3 = 4πGρR/3 R' = R/2 所以,该星球体积是地球的 1/8,而密度是 2 倍,所...