mGM/r²=mv²/r,v²=GM/r,r=GM/v²,∴r1:r2=v2²:v1²=4:1,
T=2πr/v,∴T1:T2=r1v2:r2v1=8:1,
F=mv²/r,∴F1:F2=v1²r2:v2²r1=1:16
a=F/m,∴a1:a2=F1:F2=1:16