A.Gm1m2(1/R2-1/R1)B.Gm1m2(1/R1-1/R2)C.Gm1m2(R2-R1)D.m1g(R2-R1)
A.橢圓B.拋物線C.雙曲線D.無法判斷
A.主矢、主矩均會(huì)改變B.主矢、主矩均不改變C.主矢改變,但主矩不變D.主矢不變,但主矩改變