單項(xiàng)選擇題

兩質(zhì)量分別為m1和m2的質(zhì)點(diǎn),從相距R1處運(yùn)動(dòng)到相距R2處,需克服引力做多少功?()

A.Gm1m2(1/R2-1/R1)
B.Gm1m2(1/R1-1/R2)
C.Gm1m2(R2-R1
D.m1g(R2-R1

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