(1)GMm/R^2=mg
GMm/(R+r1)^2=mv^2/(R+r1)
v=根号(mgR^2/(R+r1))
(2)GMm/R2^2=mg/6
GMm/(R2+r2)^2=4m(R2+r2)pai^2/T^2
T=根号(24(R2+r2)^3pai^2/gR2^2 )
(1)GMm/R^2=mg
GMm/(R+r1)^2=mv^2/(R+r1)
v=根号(mgR^2/(R+r1))
(2)GMm/R2^2=mg/6
GMm/(R2+r2)^2=4m(R2+r2)pai^2/T^2
T=根号(24(R2+r2)^3pai^2/gR2^2 )