1由题有
mv^2/R=GMm/R^2
v=(GM/R)^1/2
vA/VB=(Rb/Ra)^1/2
2 同样
4Rm兀^2/T^2=GMm/R^2
T=2兀(R^3/GM)^1/2
TA/TB=(RA/RB)^3/2