题干

如图所示,发射同步卫星的一般程序是:先让卫星进入一个近地的圆轨道,然后在P点变轨,进入椭圆形转移轨道(该椭圆轨道的近地点为近地圆轨道上的P,远地点为同步圆轨道上的Q),到达远地点Q时再次变轨,进入同步轨道.设卫星在近地圆轨道上运行的速率为v1,在椭圆形转移轨道的近地点P点的速率为v2,沿转移轨道刚到达远地点Q时的速率为v3,在同步轨道上的速率为v4,三个轨道上运动的周期分别为T1、T2、T3,则下列说法正确的是(   )

A:在P点变轨时需要加速,Q点变轨时要减速

B:在P点变轨时需要减速,Q点变轨时要加速

C:T1<T2<T3

D:v2>v1>v4>v3

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答案(点此获取答案解析)

C,D

同类题3

阅读下面图表,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

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