du V=Vx-u a.=ax dt :x S ↓ u是恒量 =Y d,=ay v.=V. d.=a. d (Yx=v+u du a.=d4+ dr' 两个都是 ax=a ↓ 惯性系 a,=d, v.=v. a=d a a 在两个惯性系中 a'=a 两个都是 惯性系 u是恒量 在两个惯性系中 aar r ′ = zz yy xx vv vv uvv ′ = ′ = ′ = − zz yy xx vv vv uvv = ′ = ′ = ′ + zz yy xx aa aa t u aa ′ = ′ = ′ −= d d zz yy xx aa aa t u aa = ′ = ′ ′ = ′ + d d zz yy xx aa aa aa = ′ = ′ = ′ zz yy xx aa aa aa ′ = ′ = ′ = S S ′ S S ′