Q.

If a satellite orbiting the earth is 9 times closer to the earth than the moon, what is the time period of rotation of the satellite Given rotational time period of Moon = 27 days and gravitational attraction between the satellite and the moon is neglected.          [2025]

1 1 day  
2 81 days  
3 27 days  
4 3 days  

Ans.

(1)

From Kepler's law, T2R3

(TmTs)2=(RR/9)3

TmTs=(3)3  Ts=(2727)= 1 day