2020年11月24日4时30分,长征五号运载火箭在中国海南文昌航天发射场成功发射,飞行约2200秒后,顺利将探月工程嫦娥五号探测器送入预定轨道,开启中国首次地外天体采样返回之旅。嫦娥五号飞行轨迹可以简化为如图所示,首先进入近地圆轨道Ⅰ,在P点进入椭圆轨道Ⅱ,到达远地点Q后进入地月转移轨道,到达月球附近后进入环月轨道Ⅲ。近地轨道Ⅰ的半径为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3Er%3C%2Fmi%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,周期为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3ET%3C%2Fmi%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,椭圆轨道Ⅱ的半长轴为a,周期为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3ET%3C%2Fmi%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,环月轨道Ⅲ的半径为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3Er%3C%2Fmi%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,周期为
![](https://math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3ET%3C%2Fmi%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmsub%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
,地球半径为R,地球表面重力加速度为g。忽略地球自转,忽略太阳引力的影响。下列说法正确的是( )
- A、嫦娥五号在轨道Ⅰ的运行速率大于7.9km/s
- B、嫦娥五号在轨道Ⅰ上经过P点的速率大于在轨道Ⅱ上经过P点的速率
- C、嫦娥五号在轨道Ⅰ上经过P点和在轨道Ⅱ上经过P点的加速度相等
- D、嫦娥五号沿地月转移轨道喷气飞行时,地球,月球,嫦娥五号组成的系统机械能守恒