Question

Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3v, the speed of satellite B is ____________.

Options

• 12 v

• 6v

• `(4"v")/3`

• `(3"v")/2`

Answer 1

Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3v, the speed of satellite B is 6v.

Explanation:

`"Orbital velocity, v" = sqrt("GM"/"r")  "i.e., v" prop 1/"r"`

`therefore "v"_1/"v"_2 = sqrt("r"_2/"r"_1)`

` = sqrt("R"/(4"R")) = 1/2`

`or "v"_2 = 2"v"_1`

` = 2 xx 3"v"`

` = 6"v"`