Two satellites `S_(1)` and `S_(2)` are revolving around a planet P in circular orbits of radii 4R and 9R respectively. If the speed of satellite `S_(1)` is 2V, then calculate the speed of satellite `S_(2)`.

Explanation

As we know orbital speed `V_(0) = sqrt((GM)/(R ))`
For `S_(1), " "2V = sqrt((GM)/(4R))` …(i)
For `S_(2), " "V. = sqrt((GM)/(9R))` …(ii)
Dividing (i) by (ii) we get
`(V.)/(2V) = sqrt((GM)/(9R)).sqrt((4R)/(GM))`
`v. = 2V.2//3 = 4V//3`