我国将要发射一颗绕月运行的探月卫星“嫦娥1号”。设该卫星的轨

我国将要发射一颗绕月运行的探月卫星嫦娥1。设该卫星的轨道是圆形的,且贴近月球表面。已知月球的质量为地球质量的1/80,月球的半径约为地球半径的1/4,地球上的第一宇宙速度约为7.9km/s,则该探月卫星绕月运行的速率约为
   A
0.4 km/s    B1.8 km/s     C11 km/s    D36 km/s

答案

B

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